Most of the suggestion I've heard or either too overpowered, or too complicated. Here are a few of pretty simple things that be done.
1. Increase hitpoints with the building techs:
o Medium scale building: +30% (base 39 HP)
o Large scale building: +40% (base 55 HP)
o Massive scale building: +50% (base 82 HP)
2. Allow constructors to repair 30 points of damage instead of adding a module
3. Tie star base weapons and defenses to researched techs
For example, the devastator beam would do only one point of damage if all you have researched was Particle Cannons. But at Laser V, it get the full to the full 7, and once you get Plasma, it goes even further.
What do you think?