Stacking is crazy!

Cluke: In answer to question 2.

When you do a panorama in msIce, the algorithms for the overlap are very sophisticated and that's largely what makes the program so powerful compared to other similar software. It this feature of the program you are calling upon when you use it to stack images on top of one another.

Just drag and drop the similar frames into the msIce window and it will auto align them with the most appropriate algorithm and then stack them. The software is not as good as some with hdr (stacking differently exposed images) but for straight same exposure stacking to increase the clarity it is excellent.