playing multiple loosies

There are some types of bad players that actually end up helping each other out, they make one another less bad.
When you have multiple overly loose players at your table. With so many callers the pots get very big. Big pots mean good pot odds. Good pot odds mean that it’s correct to call with marginal or weak draws, which is exactly what overly loose players do.
So having a large number of very loose players actually makes playing loose correct.
You can still make money by playing slightly tighter than your opponents preflop (although still quite loose by normal standards), and by being more aggressive (although willing to chase draws) after the flop.

I don't know if that's correct. Everything I've seen before says the opposite. The best way to win money at a table is to play opposite to the way the table is playing. In you example, playing tighter then you normally would would be the best way. If the table is overly tight, playing a little bit looser is the most EV strategy. If the table is really loose you will easily get paid off when you get your big hands, and you'll stay out of tough spots where you aren't sure what they others have. That's just how I've seen it anyway.

Yes, when they're all playing loose they improve each other's odds.
If you raise and there are five other players still in the hand, it's correct for the first few to call with almost any draw if they can expect more people to call along behind them.
Usually their calls are still bad and they're certain to have horrendous leaks in other areas, but you do lose some edge.

The size of the pot doesn't improve the odds since your bet sizes are based on the size of the pot. It does effect implied odds, but actually makes them worse (larger total sum but smaller relative to the bet sizes and pot size).

I almost agree. You can loosen up quite a lot. A lot of microstakes players make the mistake of playing tighter against overly loose opponents, if your opponents are making more mistakes it allows you to play a wider range than normal profitably, you still want to be playing tighter than a loose table but just aim for nearer to TAG stats, rather than going even nittier.

The loose play allows you to play the implied odds stuff like SCers more liberally but the hands you should really be adding to your range are Ax and Kx and even Qx, especially suited (yes, I'm suggesting you play K2s when in position). Against loose fish you'll make your money from one pair, not straights and flushes. They'll pay you off really light so you can start value betting lighter.