Missions & Complexes

Basically i haven't done missions since retribution, but i've been wanting to do some light eve playing again and missions would be cool. Now i've heard all these things of killer missions, etc..

I'm not worried about rooms with aggro groups, and spawn triggers? I mean these are still the norm? or do they all aggro now independently of you making a move on them? But i've also been hearing all this stuff of full room aggro on the more tougher missions. Stuff that would easly break your mach tank. Now it's not really a tank, but has it lost it's value in missions since i can't seem to find any mentions of it in the first few pages of the forum? I'm somewhat worried cause the consensus seem to be that you require more tank, if not even more players?

Would someone please update me a bit on how missions go like these days? I didn't really have any problems in my mach earlier as long as i geared properly. I could be unlucky and aggro to much making for more of a thrill than what i had wanted, but in the end the ship still works.

Also what seems to be the generally accepted ships as effecient lvl 4 solo ships?

Oh yea, i'm a heavy user of eve survival. It still doesn't help much tbh, checking out missions there's not alot of changes/comments regarding the retribution expansion. Except the odd mention of increased inc dmg and near deaths.

For instance, worlds collide and vengeance..

Thanks for input. Sounds like ill downgrade ships for awhile. I've never felt confident with machs tank, but it does bring them down fast. I always found amarr missions to be heavy on ewar, but comming from minmatar space might be why.