[pinkpanda3310]

I think some of those Q's are more related to the specific car and track you are planning on.

Going by what you have - 8t mmm 2200. I would be running a single 4s. If it's quite a large track then 5s.

I don't see the point in having 2 packs in series when they will be in the same tray.

You may also want to check what the track rules are in regard to hardcase lipo's.

I use dual lock velcro under the battery tray and rarely remove the tray as it works well for me.