In regards on what L2 you choose for safe bridge, No one can answer you here an exact answer since all of the existing bridge has the tendency for potential exploit due to a lot of factor.

Each L2 have their own trusted bridge. I think the greater the liquidity on the bridge means the more safety you can use it because already a lot of user trusting it. The danger on bridge relies on the liquidity provider while the user is rarely become affected because you are just using it not too frequent.

L2 has their own advantages and disadvantages so it’s up to you on what kind of protocol do you preferred but the safety is always subjective because no one knows what project will be the target for exploit.

Yes you could being in those to L2 but the thing is since you transfering from L1 expect some high fees on eth network or higher gas fee. If you only transferring a little eth then dont mind cause youll be just dissapointed with the fees. If you use eth network make sure you are engaging with considerable amount of eth to make use of the fees efficiently like 0.4eth and above sending 0.01 0.02 is a waste of gas fee.