i would be most interested in seeing the build. once i see the build i could probably oblige regarding points two and three.
i have a few suggestions for point one - getback.
the easiest way to hit someone of high ac is to use the aid another action. this applies to both grapple and attacks. if you have small or tiny flying creatures with a reach weapon (must be at least 5' of reach, considering the size of the creatures...) you can stack a rather large number of them in a pseudo-swarm (pseudo because swarm has specific meaning and rules in d&d) around the character. then all but one use the aid another to grapple or attack the character. the dc is about 15 iirc, and for every success the attacking/grappling character gets +2.
you can also cheat using sovereign glue to make things stick to the monk, adding weight. cursed stones of weight are great for this. eventually they will exceed their maximum weight and won't be able to run. heavy grav zones work help too.
another fun one is filling traps such as pits with whip cream. let them jump or fly and hit the wall of force halfway across and drop into the stuff. or toss something or someone they want into it. too light to swim in, can't breath it, too slippery to climb, even impedes jumping. hit them with a dispell or two to cancel flying, or even increase gravity....
if you give a gelatinous cube the celestial or fiendish template, that raises the int enough to take character levels. duplicate the load out on the monk onto a cube and watch them run from jello. ^^ you could give it the quick trait from unearthed arcana, one level of ranger with the wildshape acf still grants you fast movement like a barbarian at level one, level of barbarian, toss in fist of the forest if you can swing it for another speed boost.... you could get up to +40 in a few levels due to fast movement stacking, and that's not counting monk levels.
there are more ideas where those came from. ^^