Yeah the power rating graph leads to the AI making some tragic errors. Like deciding you're weak, ripe for conquest, and suiciding their entire fleet onto your border guarding technologically superior fleets...

If you want to stave off war until you can build massively superior fleets focus a bit on diplo techs and drop the odd embassy on planets and starbases, build a couple of prototype ships, and buy one or two extra survey ships from the mercenaries pool (if available) and survey heavily so you get lots of free ships from the ship graveyards. The combination of not being ridiculously weak, with really strong diplomacy helps.

Also early on get all the Open Borders as soon as you meet people and the two most evil races (Drengin and Snathi) say you like them in the diplo. It's too early for anyone to say 'you liked my enemy' since nobody really has any enemies and it slows their hate a bit.

I have not tried in the opt-in, but one thing that I do to help with the sily power curve is ask for ships from minor races. The game doesn't know they are junky as far as the power screen goes. Especially once I get free trade agreements, those are typically good for one or two free ships plus some energy credits, per minor race every time the deal expires. Later I can upgrade them to something useful if I want, or just scrap them for a cash infusion if needed.

In terms of winning the game, quality counts more than quantity. In terms of the power score it is reversed. Getting a bunch of cheap, low maintenance ships without interrupting my starbase more important functions is a nice solution. I consider it like using the minor race's as contracted military suppliers. ^.^

Maybe i broke my game some how but i do not see the ship part scaling. I turned mods off verified game files started new game designed new ship.  every drive increased mass and moves by the same amount, same wilt sensors and life support.  What am i missing? where is the now a set value with percentage increase?

yup, it is 1.7 just did a new med hull, put 4 warp drives on, mass cost for # 4 was the same as # 1... What the heck?

EDIT Ok i THINK i see the change a given component (e.g. warp drive) uses up more mass as the hull size increases but remains constant for a give hull.  honestly it does not look like a very big increase though

That will have minimal effect on me. I usually only had 2engines on up to medium, and 3 or 4 on large hulls. The rare games where I researched huge before winning,I usually dont build any. I have built my utility ships (colony, constructor, trade, etc) with a goal of ~20 move. But I can live without that.

I also typically build weapons on my escorts and armor on my capital ships. Now, I do put more def on my escorts and more weapons on my capitals, but I don't neglect either.

The sensor stacking loss I will feel, because I do keep a picket line of them parked in key space stations and worlds. Like you I play on big maps so even a large ship with nothing but sensors sees at most 10% of the map, probably less. I typically ñeed 5 or 6 of these just to see all of  my own territory.

I guess I'll have to start researching better space station sensors.