I'm no PLO8 expert, but I enjoy the game and have discussed this very concept with smart people before, so I'll do my best to contribute to the discussion.

You're thinking about the right things. The one thing to keep in mind, relative to hold 'em tournaments, is that there are no antes and thus there is less incentive to raise very weak hands just trying to steal blinds. Consequently, you should be less concerned about giving yourself a very cheap price on your raises. In this game, you are often raising because you have a good hand that can put a lot of money in the pot if necessary but that nevertheless benefits quite a bit from folds (there is no equivalent of AA in NLHE, where you have little to gain from a pre-flop fold).

So, unless your opponents fold way too much to minimum raises, I'd suggest opening at least 2.5x, more often 3x or even full pot.

As for limping, yes, I do think it has some merit, especially in early position. Especially with somewhat deep stacks, many hands in PLO8 play nearly as well multiway as they do heads up. There's a strong case for limping something like A23Jds UTG and inviting a multi-way pot, especially when the alternative is probably raising and playing heads up or getting 3-bet, not just raising and stealing the blinds.

It can also be nice to limp-reraise in EP with hands that have a lot of pre-flop equity but don't play well post-flop. That includes stuff like AA87, AKK7, etc. If it does limp around, you'll usually fold those hands if they don't smack the flop, but if someone raises, you'll have the opportunity to make a big re-raise pre-flop, which even if you don't get all in pre will enable you to see the flop with a much lower SPR and generally just shove any remotely favorable flop.