Rummikub

No — the tiles used for your initial meld must come from your rack; you may not use tiles already played on the table to reach the required 30 points (page 1).

You must place sets totaling at least 30 points for your initial meld, and a joker used in the initial meld scores the value of the tile it represents (page 1).

Yes — you may manipulate, split and recombine sets on the table (including removing tiles from groups/runs) as long as at the end of your turn only legitimate sets remain and no loose tiles are left (page 2).

A joker may be retrieved if you can replace it during your turn with tiles that keep the set legitimate, but when you retrieve it you must immediately play the joker to make a new set and use at least one tile from your rack that turn; you may not retrieve a joker before you have made your initial meld (page 3).

No — when a player draws a tile from the pool their turn ends, and players cannot lay down a tile they have just drawn until a subsequent turn (page 1).