1) There is also a command to minimise mIRC to the tray, and that is /showmirc -t
2) +v means 'voice' - it is technically meant for +m (moderated) channels. 'Moderated' means that only people with +/@ (voice/op) can speak in the channel. Although not definite, it is not always a good idea to message an op and ask for voice, it can occasionally get you banned from channels or a warning (different channels have different rules). However, if the channel has lots of other voiced users or is indeed +m (or a similar mode) then there's no harm in trying - even if you do get banned (which is unlikely), you can't say anything more than before!