1. And average of 1 hour per day is weaksauce imho. Whether it's sufficient to get the score you want, who knows. How many you should do depends on lots of things including where you're scoring now, where you need to be scoring for the schools you will apply to, how quickly you learn, and how much time you're willing to allocate to get the score you want. Also, get a tutor or take a class.
2. Depends on the school, but a higher score will never hurt.
3. A splitter is a student with low GPA and high LSAT or vice versa. Some schools are more likely than others to admit splitters (I've also heard these schools referred to as "splitters").
4. Your best LOR will come from someone who knows you well as a person. Someone who doesn't know you, the person, is likely to use generic phrases to describe you, and this does nothing to help admissions people decide whether you will be an asset in the classroom. You want someone who can offer anecdotes and specific events that helped define you in their eyes. Most schools will request that 1 or 2 of your LORs come from professors, but others can come from wherever (I actually had my next door neighbor write one for me). Anyway, make sure your LORs come from someone you've spent considerable time with, not just someone in a prestigious position.