Allying w/ minor races

Yes, it is. It's a bit harder than with major races, but possible, You also should give them money & thay will like you Sometimes giving Carrinoids your planets will makethem love you (ofcource not for free, but for lower price, they usually are good at technologies).

But keep in mind that an alliance with minors will likely get you in trouble with the majors at the later stages of the game...

Trade techs with them until they're not useful anymore...

Wait until some major race declares war on them and blasts their ships away...

...and invade their planets with a few handy combat transports that you (just in case) kept waiting nearby once their defences are no more...

I'd better support them.
I usually achieve curtural victory. My strategy is based on mass diplomacy, espionage & distabilizing my potential enemies. I don't research military technologies at all. I prefer to do what they say at any cost (even if they say to give them 2k + some good tech). So the way to survive is to avoid war & to support somebody who is in war with my potential enemies. I also avoid any alliances, because they can cause a war for my ally.
War is ugly. . .

Hmm, if i go for Cultural or Tech Victory, i usually research military techs as far as Dreadnought. Then i build lots of AMMs, until my military power is so high that the AIs don't get any silly ideas...