Miniflex is a technology that allows us to groove hard plastic during extrusion. This allows us to produce small, flexible yet ruggedized fiber cable that is extremely easy to use and can be pushed into ducts.
There is no functional difference. The VC has a heci code and the VV does not.
The short answer is yes you can.
I would recommend that on the way to Feature Pack 15 you go to Feature Pack 10.0.34 first. The 10.0.34 release was designed to be a bridge between the old and new style Tellabs cards. 10.0.34 will work with all the old cards and even work with the new bonded ADSL cards in purely ADSL 2+ mode. This makes 10.0.34 a great revert revision. Also the database for 10.0.34 and 15.0.3 are very much the same making the transition quicker and less likely to have errors.
You can go from 10.0.28 directly to 15.0.3, but I think going to 10.0.34 before going to 15.0.3 is a smarter way to go.