A:AnswerThe fps is based on the type of go pro you have. It is not based off the touch bacpac. This is just an accessory to add on to view what you have recorded on the go pro.
A:AnswerHonestly I tried to observed it because that's one of my question before I bought mine the only thing is I didn't really put time how long the with and without LCD but I observed that it's not really going to eat much of your battery, only suggestion is buy an extra battery for about $25.00 dollars only, but it's worth having LCD especially you want to see what your shooting.
A:AnswerIt comes with a few backings that you would use. Obviously the Lcd has some thickness so standard backs won't fit, but the standard cases are still used.