Hi

I'm also new on this forum, actually this is my first post.
I'm also practicing Rach 2nd right now and I've got the basics down for the entire piece so I think we can help each other out on this. You are amazingly good considering the fact that you only played for 2 1/2 years. When I was starting this piece, my friends said that I might not be able to play it because of the difficulty in technique but I managed to play every section on tempo so you might be able to do it as well. Just go for it man.
1. For me, I just start from the beginning. Well since you don't have enough time, it'll be a good idea to start from the hardest section but I like to start from beginning, learn the whole piece and be able to play it with final tempo, and then I start actually practice the piece and refine it.
2. Umm... This is my first concerto also so I can't give a solid answer for this but I don't think you should worry about that too much. Just make sure you are on tempo and on the right beat, then the orchestra will be able to follow you. On rubato sections, Orchestra's supposed to follow you, not you follow orchestra so be clear and solid on your interpretations so you don't change them every time.
3. You have to group them as a whole. For 8 notes, all the 8 notes are in one beat. For 9 notes, all the 9 notes are in one beat. etc.
4. If you work incredibly hard it might be possible. Just don't overwork yourself thou.
5. Have a solid practice on it. Work on it everyday even if it's already perfect. Get audience and play them in front of people so you experience the nerves. Perfect practice will make perfect performance.
6. The hardest parts in this piece considering technicality would be the
Un poco piu mosso section in the 1st part and
Un poco piu mosso on the 2nd part. Those are the fastest parts and require a lot of practice to get it to full tempo. I'm personally weak at octaves so
acceler in the 3rd part is quite difficult for me

7. Practice, and you might be able to do it. It's a hard piece.
For your 2nd post..
What I do with different beat right hand left hand is I divide up the note value and do the math on the exact beat on where the notes should be (if that made sense

) Then I play it
Extremely slow, getting used to the rhythm. After practicing slow for a while, I try it fast, by fast I mean medium to final tempo. If the rhythm is wavering, then I just practice them slow again.
When I was practicing this piece, I was really worried about the large arpeggios too. What I do is I put down my fingerings on every single note of the large arpeggios. And then of course the usual, practice slow than speed up.
One last piece of advise. It is essential to listen to the recordings. The 1 week I was practicing this piece, I listened to it for around 100 times. It is really important to know how each phrases go and what do to with it, and what Orchestra does at that time. Just put the music in ur phone or something and listen to it as you go to sleep. It's really effective. Trust me.
Well good luck on this piece!! This is my favorite piano piece after all
