I'm planning to run btc qt wallet and bitcoin abc's core wallet on the same PC. To avoid the 2 wallets meddling with each other, is it sufficient by defining different -datadir and -port options? Any other switches I should specify?
-datadir should be enough to avoid conflicts. Bitcoin ABC installs on the same folder by default as Bitcoin Core which corrupted my installation... it was insane, I had to sync the entire thing from day one..
Ideally, you do not want to have both on the same computer. Pick up a cheap laptop to run altcoin software, that's my recommendation. Not even VM is enough isolation, always be paranoid with these altcoin scammers.