Originally Posted by HillRider

You will probably need a new bottom bracket to match the triple crank.

Your shifters should allow shifting to all three chainrings with either a double or triple front derailleur.

Your current front derailleur should work ok with the new crank. The problem you report with the chain hitting the tail off the derailleur is common in small-small but there is absolutely no reason to ever use those gears so the "problem" is easily solved by avoiding it.