Game Help: How to get back into Pokemon

Hi all, thanks to Pokemon Go I've decided to pick up Pokemon again.

My first encounter with the series was Ruby/Sapphire and I played these two extensively. I later picked up Diamond and played through it once or twice. At some point I transferred everything I had caught from R/S/E to my Diamond cartridge. I never got a copy of Pearl but played about halfway through Platinum and Heart Gold. This past week I tried to find all my old cartridges but only came up with the Platinum and HG carts, no clue where Diamond (and 95%+ of my old Pokemon) ended up.

So at this point, I'm debating whether to get a 3DS and which of the newer games to get with it or just playing through Plat/HG first. My question is, how many of the Gen 1 + 2 Pokemon can I get in any of the 3DS games without having to play through DS games and transfer? I definitely want to get Alpha Sapphire or Omega Ruby plus at least one of the gen 5/6 games but I'm concerned I'll have to spend a lot of time on an older game for most of the Gen 1 dex.

Also, I've been playing a Leaf Green rom on my phone and it's so much better to play at fast forward speed. Is there any legit way to play this way on a real cartridge/device?

When I played through Omega Ruby I decided I would start my Pokedex from scratch and surprisingly it didn't take that long (with the exception of some Event pokemon). There are tons of Pokemon in X and Y and if you have Wifi you can go to the trade corner on here and ask for help completing the Pokedex.

Now with the PokeBank you can transfer Pokemon from X/Y to Omega Ruby/Alpha Sapphire so you don't even need to trade except for trade Evolutions.

I'd say grab that 3DS and just plunge into X/Y since you said you're gonna grab ORAS anyway. There are plenty of Gen I and II pokemon in them. You could probably skip Black/White if you wanted (even though they're too of my favorites).

If you like Star Wars, X and Y are sort of like The Force Awakens. Like a kinda remake of Red/Blue with a lot of different stuff.

You should play Pokemon GO, if you want to meet your friends.

First off, glad to see that GO is bringing people back :) To answer your first question, no you can not catch every Pokemon in just one of the 3ds titles. You can get a really good chunk of them through OmegaRuby/AlphaSapphire and X/Y, but there will still be a few odd balls. Of course, you could always offer up a semi-rare starter on the Global Trade Station (GTS) and get pretty much any Pokemon :P

To answer your second question, yes and no. There is no way to put a speed multiplier on a battle, but you can remove battle animations and speed up text speed in the game settings.

I recommend that you play through one of your Gen4 games before deciding on buying a 3ds or not. This way you will know if you want to continue, and you will have one part of the transfer process already complete. If you want take that next step, you can either jump right into X/Y or ORAS, or buy Black2/White2 (used, don't pay full price) and play through that too. It's a great game... I doubt you will feel bad about it being old or whatever :)