G'day LPA,
1. If you're commuting to Spain you'd be absolutely mad to do anything else but take the C class tickets. With that length of commute you'd soon burn out with ZEDs and economy seats, so don't sweat it. Take the decent seat, collect the miles and don't worry about the $2000 you never saw.
2. See CRJ's reply.
3. Seeing as AJX aren't hiring at the moment, if successful you'd be flying for AJV. AJX may have a few extra pilots but that's not the case on the freight side and I've certainly not heard of any of our guys getting 'short months' (apart from the > 60s who are required to fly fewer hours). Plan on having 11 days off per month (AJV) and the ability to add your 2 vacation days and you won't be disappointed. Plan on getting part-time and you will be.
4. See CRJ's reply and delete 'why' from your brain.
5. You get $550 accommodation allowance per month. This is used to pay your hotel bill when in NRT and not on standby. All downroute hotel rates are taken care of by the Company. You get $50 refunded to your salary for each standby day. AJX spend more time in NRT than AJV but I don't think that will be a factor for you. I think an average month would see you paying for 6-7 nights in the Excel or Garden Hotels (most people stay at the Excel) at a rate of JPY5775 per night.
Sort your logbook out before you come. JCAB are quite fussy when it comes to the niff naff and trivia (never mind the big picture) and, as a result, the Company are too. Huge piles of shame will be heaped upon AJV by JCAB if a pilot's logbook is found wanting, so they ensure this doesn't happen by making sure you're squared off before you come.
PS: Hurry your application if possible. Rumour control suggests the total number of pilots in AJX + AJV is reaching critical mass and judicious cross-pollination would mean no more pilots required. Just mumbled rumours but I wouldn't hang about.
Okay, enough of this, I'm off to the pub......