I was wondering if I wanted to get into this game casually just to have a few balanced games.
What would you guys recommend?
Are the character starters good enough? And still available in the E.U.?

Also do I need to double up or triple up on them to have enough dice?

I'd like to get the Boba Fett starter for sure.
Would I need 1 or 2 copies of the 2 player starter?

Is it worth picking up several rivals boosters? And if so, how many for casual play?

To answer all of your questions:

1. I would NOT recommend Rivals or Allies of Necessity; they're not good for casual playing, and in fact I've rarely used any of the cards in Allies--and I've played an extremely wide range of decks. My favorite sets are Legacies and Awakenings. Would definitely recommend. Empire at War is probably the only set I would not recommend, but that's just because very few of the cards actually synergize well. It's also a very offense-oriented set, whereas I'm a defensive player. Still get it, though; it's best to fill out your collection.

2. Yes, the starter characters are average to good (aside from maybe the Grievous starter characters; they're pretty situational and can be good, but it's not a great starter deck). Idk what E.U. means lol

3. DEFINITELY double up. You don't need to triple, but you can if you want.

4. If you get the Boba starter, get the Obi-Wan starter too (the one with Han Solo).

5. Get two copies of the two player starter. Each of the characters only comes with one die, and you'll find yourself begging for a second copy of many of the cards.

6. See #1.

Hope this helps! If you have any more questions don't be afraid to ask.

Thanks for the feedback.
I noticed amazon has some stuff cheap. (especially Legacies, the price of the others seems to skyrocket)

I would prefer to focus on the prequels and OT.

If i'd get Luke 2x and Fett 2x. + 3 boxes of Legacies that would have me set?
Or would I need some previous sets to have a balanced pool?

Awakenings seems rather pricey still. And rarer to find.

Spirit of the Rebellion I can get my hands on cheap as well. But it seems more sequel trilogy-centric?

I'm mainly hoping to make a deck focussed around Vader and one around the Fetts vs a deck themed around a character like Leia, Mara Jade or the likes for the misses.

So, Destiny doesn't deal with the Legacy Universe. It does OT, ST and PT. And there isn't going to be a set that focuses specifically on one of the trilogies; rather, each set has a balanced mix of all three. So if you want a Vader deck, there are Vaders in Awakenings, Spirit of Rebellion, and Across the Galaxy. Spirit of Rebellion definitely has some outstanding OT characters IMO, and if you can get Awakenings, then do (it's my favorite set). If you want a balanced pool, I would steer clear of the newer sets, as everything they throw out there is above and beyond overpowered compared to the first 3-4 sets. Definitely get Aw, SoR, EaW, and Leg, and if you want to then you can go higher from there as well. And 3 boxes isn't always enough, tbh: if you want to be "set" for a set of cards, you'll need at least 6-8 boxes lmao.

6-8? Wow...
Oo; That's quite the investment.

Thanks for the feedback!

6-8 display boxes is only if you want to chase legendaries.

For casual players, 3 display boxes is good. With even distribution you end up with 2 of each rare, 2-3 of each uncommon, and 5-6 of each common. Since even distribution is unlikely, ideally you would balance your collection by trading with other casual players who have gotten into the game with the discount prices. Unfortunately, I haven't seen any trading.