I usually just insert my canulas manually. I hate the way the Sof-Serter works. I'm used to the Cozmo Cleo's. I loved those.
As for your other questions... I just pull it out, no I don't use the bra attachment. I like the belt clip and just keep my pump on my waistband, much the way we used to carry pagers around.
As for supplies I keep with me, I have a see-through plastic make-up bag that I keep my meter, strips, lancet, vial of novolog, and the two extra pieces of the reservoir in. I don't carry any extra sets, tubing, etc. Unless I'm going away from home for more than a couple of hours...then I throw an extra set, IV Prep, and reservoir into that same make-up bag. But, I'm a stay at home mom, so I don't go away from home all that often...
I typically test 12 times a day. More if I'm extremely low or high. I will do corrections if, two hours after eating, I'm not where I expect to be. For lows, I test every 15 minutes for an hour.