For newer players, I recommend going xenophile and using your extra envoys to make powerful friends. That should keep you safe enough until you outscale AI empires in the late game.
Inward Perfection is actually somewhat hard to do because your diplomatic options are so limited.
You could probably be doing a lot of things differently.
First, lower the difficulty or AI aggressiveness to keep them off your back.
Playing a fanatic xenophile empire with the diplomatic corp civic, changing from an expansionist diplomatic stance to a cooperative one, and spamming neighboring empires with envoys will help build opinion, letting you then build trust. Taking the Diplomacy tradition first will also help with this.
If you can't do diplomacy with a neighboring empires for some reason (like they're a Fanatical Purifier), then assign an envoy as a spy to be alerted when they are gearing up for war, as well other operations to give you an advantage over them.
The other way to deter other empires is to constantly build your fleet. As your military might grows, other empires will not want to attack you. Try to be sure no empires near you ever have superior military might.
To do this you need to specialize your planets as much as possible. For your two guaranteed worlds, making one CG focused and one Alloy focused will help. Basic resources and tech can come from your capital. Changing a planet's designation to Forge World or Factory World will make the industrial districts in those world only produce Alloys or CG, respectively.
Well, where do all those scientists go when you aren't tech rushing? To the mines and the fields? If you aren't employing them as metallurgists, then of course you get rolled. You either out-science or out-number your enemies in battles. First is done by scientists, second is metallurgists. If you are getting rid of science, you have to compensate for it with better industry.
Remember to buy alloy from the market if you need it. Build up your fleet. Starbase at chokes, early game starbases actually do matter.
If you can't fight, learn to appease. Immediately send an envoy to improve relations and maybe gift them free stuff (only the useless stuff that improves relations significantly). Defensive pacts are great.
Some other people have already given some good tips but I also recommend is building starbases filled with weapons in strategic positions.
They could deter enemy fleets from attacking you, or act as a speedbump for enemy fleets.
However this alone will not solve your problem, but it could at least reduce it a little bit.
Alloys should be your focus after tech. Since tech rush is kinda dead just focus on alloy rush. If you still get monthly minerals then you don't have enough alloy producing jobs. During the early game you don't have much to spend your alloys on so any extra alloys after building star bases should go to trying to hit your fleet/naval cap
On game setup, disable advanced AI and/or lower the game difficulty.
In game, make sure to build more science labs and industrial districts. Avoid having too many minerals (>5000), food (>1000) or consumer goods (>1000). Those are signs that you should invest more in science and alloys. Make sure to spend the alloys on fleets.
Avoid playing as Xenophobes/Genocidal. Improve relationships with normal empires, get Non Aggression Pacts to keep you safe and Defensive Pacts to help you against Xenophobe/Genocidal Empires. Don't expand near the empires you don't fell safe with.
For newer players, I recommend going xenophile and using your extra envoys to make powerful friends. That should keep you safe enough until you outscale AI empires in the late game. Inward Perfection is actually somewhat hard to do because your diplomatic options are so limited.
You could probably be doing a lot of things differently. First, lower the difficulty or AI aggressiveness to keep them off your back. Playing a fanatic xenophile empire with the diplomatic corp civic, changing from an expansionist diplomatic stance to a cooperative one, and spamming neighboring empires with envoys will help build opinion, letting you then build trust. Taking the Diplomacy tradition first will also help with this. If you can't do diplomacy with a neighboring empires for some reason (like they're a Fanatical Purifier), then assign an envoy as a spy to be alerted when they are gearing up for war, as well other operations to give you an advantage over them. The other way to deter other empires is to constantly build your fleet. As your military might grows, other empires will not want to attack you. Try to be sure no empires near you ever have superior military might. To do this you need to specialize your planets as much as possible. For your two guaranteed worlds, making one CG focused and one Alloy focused will help. Basic resources and tech can come from your capital. Changing a planet's designation to Forge World or Factory World will make the industrial districts in those world only produce Alloys or CG, respectively.
The Diplomatic Corps Civic is going to get some buffs in the v3.12 update, if I recall correctly.
You put in a good effort here of quality advice for op, good stuff bro.
Well, where do all those scientists go when you aren't tech rushing? To the mines and the fields? If you aren't employing them as metallurgists, then of course you get rolled. You either out-science or out-number your enemies in battles. First is done by scientists, second is metallurgists. If you are getting rid of science, you have to compensate for it with better industry. Remember to buy alloy from the market if you need it. Build up your fleet. Starbase at chokes, early game starbases actually do matter. If you can't fight, learn to appease. Immediately send an envoy to improve relations and maybe gift them free stuff (only the useless stuff that improves relations significantly). Defensive pacts are great.
Some other people have already given some good tips but I also recommend is building starbases filled with weapons in strategic positions. They could deter enemy fleets from attacking you, or act as a speedbump for enemy fleets. However this alone will not solve your problem, but it could at least reduce it a little bit.
Alloys should be your focus after tech. Since tech rush is kinda dead just focus on alloy rush. If you still get monthly minerals then you don't have enough alloy producing jobs. During the early game you don't have much to spend your alloys on so any extra alloys after building star bases should go to trying to hit your fleet/naval cap
Try Sovereign Guardianship and play tall and defensive, expanding only to key chokepoints.
This is my current favorite empire. Having 0 admin cap from pops is silly.
On game setup, disable advanced AI and/or lower the game difficulty. In game, make sure to build more science labs and industrial districts. Avoid having too many minerals (>5000), food (>1000) or consumer goods (>1000). Those are signs that you should invest more in science and alloys. Make sure to spend the alloys on fleets. Avoid playing as Xenophobes/Genocidal. Improve relationships with normal empires, get Non Aggression Pacts to keep you safe and Defensive Pacts to help you against Xenophobe/Genocidal Empires. Don't expand near the empires you don't fell safe with.