All help would be very much appreciated!
I've never used much effects in my live guitar rig, but I have a Digitech RP50 (multi-effects and amp simulation pedal) and need help as to how to set it up through my amps (Mesa Boogie Rectifier) FX loop, so that the RP50 will only engage when engage the Mesa's FX button. I only want to engage the Digitech RP50 for solos and leads only.

Here is my main question... How do I set the pedal to use the pedal's effects ONLY (reverb, delay, chorus, ect) without using the pedal's amp simulation at the same time? To put it simpler, I only want to use the pedals effects on top of my Mesa tone with the pedal's amp simulation disabled...

Thanks for your help!
You'll get better sound if you just buy some new effects pedals. Separate ones, too. Not multi-FX.

Sorry to say, but I can't help you other than to say that. I don't own one of those, nor do I know anything about DigiTech.