Since you already have the CFI, is there some place around where you can instruct to build time while waiting for a regional to call? You never lose anything by applying. I'd say apply where you want to work and if they call, great, if they don't at least you'd be working as a CFI (it
is current, right

?).
Where do you live, where do you want to live, what are your end goals? Are you willing and able to move? Have a road map and stick to it. Being 35 won't hurt, it might even help, as most CFI schools I worked at liked the "older" folks because they were more dedicated, mature, etc. Folks in my new hire regional class ranged in age from 21 to 56.