I am going to run Mask of the Pirate Queen, I only have two PCs. One is a smuggler scoundrel, one is a bounty hunter assassain. I gave them 20 extra XP each, but is this too little? The smuggler diversified his character quite a bit, focusing on piloting, skullduggery and stealth, as well as talking. The bounty hunter is basically left to fight by himself. I am considering giving them an NPC ally. Neither of them is good with slicing, so this might be an astromech droid. Should I give them more XP to start off with, give them the droid, or will they be fine?

Don't know the adventure but it may be, play a session and if it's tough give them a big post session xp payout to make up some ground. Give em a NPC droid tag a long like an R2 or protocol unit for some skill shortfalls and don't be stingy with gear and they should be fine I'd think.

If you're playing a published adventure, you will need to do some scaling. MofPQ doesn't strike me as really for beginner characters either. A droid is a good idea. Beyond that, I don't think XP really solves the main problem of scaling (at least not right away): you only have two targets instead of, say, four, so any damage output is going to be concentrated. Basically, the two will go down more than twice as fast as four, so you might need to reduce minion numbers, cut Rival WT by a 1/3rd, etc.

As a general rule, though: yes absolutely, the game itself plays fine with 2, or even 1.

Edit: it's probably worth a noncommittal lead-in session to see how it goes before you launch into the main adventure.

I once ran with two players, then one didn't show for a few sessions and I played them as an NPC until they came back. Conveniently, around that time, I had also convinced one of my friends to play and soon after found another player. For the MotPQ issue, I would say that it might be a good idea to weaken the enemies, as 2 gunslinging rogues is a lot less firepower than 3 or 4. Even if they both go heavily into buffing their attack power, they'll still be behind a group with similar XP levels but extra characters. I'd recommend giving them an NPC buddy or hunting down someone else that might be interested in playing

EotE runs wonderfully for 2 PCs. I ran the beginners box for just two NPCs as a test session and we all had an amazing time. Small groups really give the GM a chance to work with the characters and make them much more a part of the story. The thing with running a published adventure is they tend to be designed and balanced for a typical 4-6 person party so you will need to work around that. With experience you will be able to see the things that need changing easier. Whafrog had a great ideal about running a noncommittal first session that will help you identify your players strength and weaknesses.

No, Han and Chewie were a two-man show during most of their years and they worked perfectly off each other.

True they had a lot of specs, so I guess you need to adjust the XP output. And your players should discuss who is going to stat into what skill group (social, technological, combat, flying/driving, investigative) and respective talents. If they have a ship, both should be able to steer it, that is important imo.

Really think of Chewie and Han and think what specializations both probably have to give your players advice on how to manage this.

Also an Astromech as a companion NPC is truly a helpful asset, especially because none of your players is mechanically inclined.

My campaign started out with 2 players. I didn't run any published modules until more players joined, so I was able to scale encounters as I created them. Although combat was still a bit tough for them at first. (one is an Archaeologist, not very fighty) They had R4-W9 from the CRB adventure for computer and mechanics checks, which helped out.

When I had a bigger group, the Merc was good in Leadership, and I was able to do bigger battles by having him command a small group of minions. So, instead of xp, you could also increase the award to include another share or two, and use that to fill in with hirelings.