Hi

I'm coming from a background of 200 and 400 NL(winning player) 6 max online and my games live are now 500 NL 9 handed.

Preflop tendencies:
Players play very loose and passive.
Preflop aggression is almost always a premium hand.
The odd ones out are strong "online players" who is easy to spot, and maniacs who are bluffing too much is also easy to spot.

Live players tend to vary their raise sizes preflop, which often gives away the strength of their hand.



Preflop strategy: I try to play as loose as possible, but playing too loose 9 handed and you'll run into too much trouble.
My open raises are minraises or 3x, my opening range is loose so I don't think 4-5x pre does me any favors.

Limping:
I try to tone down my aggression, so I don't mind overlimping quite a bit.
I even open limp, if the table is either very passive or at least one player at the table always sees the flop regardless of raise size.
In these cases I can also decide to limp a big hand.
Yes it might seem obvious,but recreational players don't care if I'm repping aces or not.
I'm building a big pot preflop instead of going 7 way to the flop after raising under the gun.


Postflop:

The norm is the same as preflop: Passive and not much bluffing going on.
When you get raised, be extremely cautious!

Coming from an online background, I'm not used to playing in 5 way pots.
The good old top pair good kicker can obviously easily not be good, so it's important to make adjustments.

Bet sizes is so different.
Players will often bet 30 into 115 on the flop with top pair, or maybe 50 with a set.
They don't think about how much the bet is compared to the size of the pot.
Whenever someone bets more than half the pot, expect them to show you the nuts.

My biggest problem by far is that I give my opponents too much credit.
"I'm at the top of my range here"
"I look so weak after taking this line".
The reality is that your opponent will look at their own hands and play accordingly.


Are my assumptions correct?
Any tips for more adjustments?

Welcome to the forum, OP. There are a bunch of threads on this, so I'm going to lock this one, but your assumptions and adjustments are pretty much correct. I think your post-flop betsizing comments are exaggerated, and your PF raise strat is controversial, but many online-to-live players agree with you.

Please read the related threads in the "best of LLSNL" sticky, and use the search function for more such threads.