Hi
The Doubletree is not quite in the City Centre! But its an easy walk, just under a mile. Taxis are everywhere so no problem with that.
Pubs - Definitely the Prince of Wales, then The Grill if you like whisky.
for restaurants it depends on what type of food you like - Aberdeen has a big selection. Try The Nazma if you like Indian.
Montrose and Cruden Bay are quite far so you will need to book a minibus for seven people plus clubs or two taxis. Royal Aberdeen is very close so just get taxis. Newmachar is probably taxis.
I work as a professional Caddie so if you need a caddie let me know. Royal Aberdeen has its own caddies (£45 plus gratuity) but for the other courses you may need to book privately if you want one.