Comping with V-drums

Have just hooked up my V-drum setup (just a Roland portable TD4KP...nothing fancy) to my recording setup and starting to use it to lay down grooves. Trying to use comping and frustrated with a couple of things. Here's what I'm doing:
1. Generally have a piano track (my primary instrument) that I want to lay down bass and drums under and use a few grooves to assemble a song before bringing in a singer or horn or whatever
2. I set up a loop region (4, 8, or 16 bars usually) and record a number of versions of basic drum grooves down (I'm a passable drummer) to experiment. 
3. I have comping set with Store Takes in a Single Track and have tried both settings for Lanes and overlap
 
Regardless of setting, I get clips that don't extend the full length of the loop AND about half the time the downbeat is at the end of the previous clip, causing all kinds of extra clip lines. I have learned to use the comp tool and 'heal' all the clip breaks to put in my own, but I can't make them all full length (e.g. 8 bars). This makes editing really complicated because I can't just select a clip, hit Shift-L and Shift-Space to start listening and selecting. 
 
What am I missing?? Should I be recording with Quantize on? That would put me back in Step Sequencer sounding grooves...
 
Help...please??