quick ableton question

[Smiley Man]

hi guys

ive been messing around using the send/return on my mixer with ableton using VSTs etc so basically its setup like an FX unit with infinite affects but ive got 2 small problems

firstly, theres always a small delay between the track running through the FX loop and the original, ive messed with bufer sizes etc in the settings but i cant get it perfectly in sync. tis pretty important for cue points etc is it possible to get it perfectly in sync?

also is there any way to assign a different midi map to each VST? for example if i have a flanger and phaser and want to assign the midi controller to each one individually, at the moment even though im using the keyboard and if i set P for example to the wet/dry control of the flanger, even with the flanger switched off i cant then assign P to the phaser, it still controls the flanger

i cant afford a midi controller with millions of buttons so wanted to be able to set a different map for each affect

i'm probably over complicating things but spending £5 on a secondary soundcard and downloading the ableton demo is a lot cheaper and more versatile than an external FX box