well i've checked ur tool.
first of all its done extremely inefficient. in state of doing nothing but reading the game infos it allready consumes more cpu than the game lolz.
i've written a small tool doing allmost the same job just for you to see that its easily possible to get all that data, without having that much cpu usage.
beside that fact the gui oscillating like hell

to prevent that you should ad timers or compare current value with the last set one, and update the gui only if the value have changed.
well as you can see there's something wrong with ur distance formula. you should recheck it. (just easy maths :P d(P1,P2) = |sqrt( (P1x-P2x)^2 + (P1y-P2y)^2 + (P1z-P2z)^2 )| )
now to get to the functions. a farm radius would be usefull. using a target radius is absolutely useless, cuz the bot should auto detect and select the closest mob.
well beside those things it looks not bad =)
maybe a small tip how to fix the problem with the cpu usage. the problem is the UpdateTarInfo() function.
u're looping through the complete moblist, each time.
once u've found the selected mob (u're not even leaving the loop! you keep looping through the rest), u're collecting the data you need to display.
why don't you set the mob_base as a global variable?
once u've selected a mob you set the mob base and now to get the data, there's no need to loop through the moblist again.
well

's my example code.
before coding a tool you should start thinking about the most efficient way to handle everything. well simply start coding would be way faster, but u'll notice that its way harder to fix stuff or even add stuff, if there's no planed structure.
a bot should always work like this:
if target selected
then kill it and pot and display info
else check for mobs around you; select the closest
thats all. as you can see listing mobs around you is only needed once every few seconds. since thats the hardest work of all you should try to reduce the number of actions.
your bot is even listing the mobs, while its potting or using skills

and it even doubles that, with listing the mobs again while getting selected mobs info.