Confusion about `unloadwallet`

It’s not clear to me how unloaded wallets behave in Bitcoin Core v0.17.0.1.

If I create a new wallet with createwallet, add a receiving address to it using importmulti, then unload it using unloadwallet:

  1. Will bitcoind still detect payments to this wallet’s address(es)? (seems yes)
  2. If yes, will that detection happen only when I use loadwallet again? (seems yes)
  3. If yes, will that require a rescan of (recent) blocks? (I’m worried about how long this might take, if it’s been months or years since I last loaded this wallet.)
  4. If yes, will that be a problem on a pruned node?
  5. If yes, should I avoid this multi-wallet feature on a pruned node, or is there a safe way to use it without risking large re-downloads? (e.g. never unload it)