My standard open at 1/2 , 2/5 and 5/5 is 5x, and with limpers in front 5x-7x.

This is really just because if you 2.5x, you will honestly get 6 callers. I'd rather 5x and get 1-3 callers and narrow their ranges quite a bit (and the pot to the flop is still the same size), rather than 2.5x and get 6 callers.

If the game is playing tighter though then I'd start opening smaller. Given that ppl 5x and flops go multiway often, this means that the SPR on the flop is often MUCH MUCH lower than in an online game.

Live - effective stacks - $550 at 2/5. Open to $25.
Two callers, pot on flop ~$75. SPR 7
Three callers, pot on flop ~100. SPR 5.25

Online - effective stacks - $550 at 2/5. Open $12.50
One caller, pot on flop ~30. SPR 17.

So on average, the most common situation in a live game is an SPR of around 6 (unless stacks are deep) and in a live game the most common situation is an SPR of about 15-20.

This is a SIGNIFICANT difference. People way overvalue implied odds type hands (SC's etc) OOP in live games imo. Hands that can make top pairs go up in value with SPRs so low.