RE: Masks/Wipeout for Blocks
Ah, yes. The vaunted masking issues of ADT.
This is something you'll need to experiment with & see what makes the most sense for what you do. AutoCAD Wipeouts will work for both acad & ADT objects (just use the draworder to bring stuff forward or backwards). Mask blocks are great for ADT only stuff.
For something like detail bubbles, I would utilize the masking utlility built into MTEXT. For other stuff, don't try to use Wipeouts & Masking Blocks at the same time. I remember using polylines alot for mask blocks. Once I got a mask block I liked I stuck it on a tool palette & used it from there. I don't remember the exact order of how I went about getting it onto the palette, but I think I figured out just by playing around with it until it worked.