Anything I should know before borrowing on a site like marginfi?

I found out about lending and borrowing recently and I wanna borrow some usdc to invest in other crypto and use my solana as the collateral. I thought about swapping my sol into eth and using Aave as they seem more trustworthy, but id rather have solana as i think itll go up more than eth this bullrun.

So if solana drops below a certain price my collateral will be liquidated, how do I find out at what price this would happen? What would you generally consider a “safe” LTV? Is going for the whole 80% a bad idea?

Is marginfi a decent site? I would use kamino but it says they dont work in the uk.