At first: Welcome to you, I missed that.
Then: To #3 I would not like to have another modeling pedal in front of the AD30VT. You will be turning knobs more then playing guitar. I know what I say

. I had several multieffect pedals, and only after selling everything, i increased my musical abilities (slowly, but i do).
Then to #1: Hey, the Vox has allready the sweetness of the tubes, you don't have to ad this
#3 I use a Marshall Bluesbreaker for that purpose. You can use it as a booster, then you only have to set volume. You will be able to "blow" the channels of your amp. Another mode ist the overdrive, then you can set Drive, Tone and Volume. The tone knob controls mainly the high frequencies. That's enough for me.
The EQ of the vox works very fine, no dramatic changes but even enoh to shape the tone. The most changes in tone come from different settings of the Volume, Master and Gain knops. Try for example Master full, Volume full and the gain softly fron zero to the point you like. You will see: The vox can create very nice tube-like tones at the point where it "brakes up".
Or vice versa, full hain, and the shape over the volume. For EQing, the middle frquencies are the most important.