Everyone is entitled an opinion. I think you might be jumping to conclusions a bit too quickly, however:
1. A boarding ship is weak on combat yes. But a successful board doubles its firepower (1 ship -> 2 ships). Better yet, the opponent is instantly neutralized, instead of taking a minute of your weapon fire or whatever. Plus he starts pulling DPS from his own fleet, diluting what you have to take.
2. An unsuccessful boarding attempt weakens the enemy ship due to crew loss, reducing its effectiveness.
3. Just knowing that boarding pods are a risk can force the enemy to max out PD and Marine modules, diminishing the firepower on EVERY fleet. If you don't know why boarding is so risky, consider what happens when a 10 ship fleet tries to invade a planet guarded by a two ship fleet. If the two ship fleet is destroyed but manages to board command, guess what? Invasion goes home, better luck next time!
Regarding repair and salvage, yes random number generators are random. Very low even, but they add up. In my current game I have received 4 salvage opportunities from roughly 10 combats with R&S, which is probably unusually high. In the previous game I got 3 salvage opportunities from 15+ combats with R&S. These are salvage results from the first 50 turns. None of it much matters until you go high enough in the trees to find technologies that are closed to you, and by that time you'll have scores of combats generating random numbers. If you are playing as SuulKa, then the entire calculation changes.
Another word about repair ships - the ability to repair a fleet in hostile, neutral, or undeveloped territory is quite nice. One ship doesn't offer much, but when the frontier world is being attacked every 3 turns, needs a garrison but cannot repair it, you'll find that your repair ship is the MVP. Like all support ships, they can't substitute for armor in a fight, but that's why they're called support.
Bottom line is that you're free to play as you like. Don't complain that the game is bad if it offers too many options. If you don't like boarding or repair, then fine - never use them. I certainly will!