1. A few vehicles can camp a building and block entrances, leaving it next to impossible to repair correctly

2. Even when 1 or 2 engineers are in a building it undergoes massive internal splash damage which in a large hit kills everyone inside.

3. In a "well played game" base/building destruction is by beacon placement.

For these three points, building and vehicle repair should be increased to balance both attacking and defending people, or at the very least be a server side option to make the game more balanced.

I don't think you should gain extra money, only that pts should be increased. That would balance this aspect of the game, since in C&C a player can turtle well for long periods of time and can only be defeated by a player or in Renegades case, a team of greater skill level. In my experience, defending teams play just as hard, or harder then attacking teams with little or no cash flow, which naturally should get that team more points when at a greater disadvantage in the game.

Example... your barracks and power plant is destroyed, then for any kill done as a regular free character you now get double the points for your skill in utilizing lower class characters without access to higher technology. It's only logical that handicapped teams become balanced when at an extreme disadvantage to compensate and give them a fighting chance regardless of skill level.

This also makes the other team have to enter a building with infantry to clear out the engineer nests, it makes the other team have to work as a team against a weaker foe with weaker equipment. And thus, the balance is maintained if both teams power and barracks is out, and makes the game cool.