No, you can only reproduce one sensation at a time. If you send a new sensation while another is being reproduced, the first one gets cancelled.
You can't send various sensations to different muscles at the same time but you can send one same sensation to several muscles at once.
Yes, if there is a sensation that must reproduce immediately, you can prioritize it to the one that was already reproducing.
The development kit is more powerful and comes with full service.