Everyone at the table has been revealed. Is there a point to doing the Clue Phase?

No. You may skip this phase now.

If I iplay an Investigate Misc. Action Card in a 5-player game and I have the FTT, that entitles me to give out 5 clues. Can I give a 2nd clue to someone?

No. We don’t want anyone quickly targeted nor more easily identified via multiple clues in a single round. In this case, your investigate card would not give you the 3 clues to which you are entitled.

You could wait to use it when you don’t have the FTT.