Codeshares my friend - look for a Star Alliance or One World airline and most likely they will codeshare with partner airlines - if you can find that you will indeed have one ticket and one checkin for luggage
a month between SR and PP would be great - plenty to see and do to keep you occupied. Maybe not a month every year, but might depend on the friendships you make while you are there. In PP I suggest the Embassy Place Apartments - used to be Accor, maybe still is - lots of long stay residents who work in the embassies and are lovely people
there are 5 categories - most of them ask for a yearly income rather than a large lump sum.
But to your point: if you had $1m in a bank account where else would you choose to live ? One of the many things I love about this place is if you’re here on a budget it’s awesome, and if you’ve got some cash to splash it’s even more awesome