I try to look at something every day. Before a tournament, I try to look mostly at middlegame stuff, as my opening reportoire is something I've used for so long I rarely need to review it. Also playing lightning is NOT considered "practice" :-)

Generally, yes. It is often a good idea to move the "h" pawn to h3 to create "luft" (prevent backrank mates), but other than that it is a good idea to keep the position intact as much as possible. An exception is when the fianchettoed bishop is on g2. The bishop protects h3 and f3, so obviously this is a stronger castled position (as l ong as you can maintain the bishop there. If it's exchanged off...the king position in noticably weaker than the standard f2,g2,h2 "shell".

Yes, whoever told you that was mistaken. Opposite side castling is an aggressive stance, and you plan about using pawn storms to attack the castled king is a typical plan used by both sides. There is a saying in such a situation that the winner will be the one who is the "Firstest with the Mostest!" And that is generally true.