Venlafaxine has some serious seizure risks when it is mixed with stimulants (including cocaine) if I recall correctly, which is the main issue I believe.
yes SSRIs/SNRIs ruin basically any drug. The only drug I can think of that wouldn't be affected by effexor's interactions or enzyme inhibition would be morphine, or either of the morphones.
Taking any stimulants will risk seizures, serotonin syndrome, or hypertensive crisis -- and most opiates (hydrocodone, oxycodone, codeine, etc) need to be metabolized by certain enzymes which I believe venlafaxine inhibits