I am not at all 'qualified' to answer all your questions but here are my thoughts. It may be hard for you to live the way you want to under your parents roof but that will only be for a certain amount of time. For the time being you can just do the very best that you can do! Keep educating yourself, keep watching documentaries that show you the right path, understand the reasons why this lifestyle is the best for you, the planet and the others we share it with. You have made the right decision...it may just take some time to implement given your current circumstances. Don't loose sight of the bigger picture...it will all be your choices and no-one else's soon enough. Do the very best you can...keep your head held high...and know you are making good choices. I wish you the best life has to offer and am proud of you for finding the vegan way so young. Good luck Youngvegan!!
Start with 2000-2500, or more. Try to find your maintenance calories on some calorie website. (http://www.freedieting.com/tools/calorie_calculator.htm)
And heres the thing, its your life, you eat as you desire. If eating raw/rawtil4 makes you feel great and people tell you this isnt healthy, or whatever bs excuse they try to pull out of their ass... Show them your blood results (assuming youre doing everything correctly, they should be great), and/or tell them to jump on the lifestyle and try for themselves. Tell them a 3 day or a week challenge. (its obviously not enough, but it should be enough to make them feel so good and energized that they wouldnt question you anymore).
Remember this- Undercarbed people cant think properly haha, jokes of course, but it is true that if youre undercarbed you cant think/function as properly as you normally could.
I never "asked" my parents. I told them. Veganism wasn't something I was going to ask someone for permission to do! You can tell them that you have decided to be a high fruit vegan, and that you are on the path to health! Explain everything you can to them. :)
I remember when I got into this lifestyle and naively I basically asked my parents permission too. Yeah they thought I was crazy for a year, but eventually accepted me for who I am now.
Wanting to be the healthiest you can be is a great aspiration and I commend you for pursing it! Unhealthy people have a hard time understanding why healthy people want to be healthy. It sounds odd to us, but that's exactly how my unhealthy family members think so don't worry if your family doesn't understand you. It sounds like your mum is a little understanding though.
For calories. I roughly use this calculation. 10 calories for every 1lb of weight. For example, say I weight 150lbs then I will need to eat 1500 calories just to maintain that weight. If I want to be energetic and active I will double that number. So 1500 X 2 = 3000. So I will eat 3000 calories because I am active and want to feel energetic. It also comes down to hunger of course. You should eat until your full. If you're not full and you're still thinking about food then you need to eat more.
I hope that helped.