I triggered the event with Albel my first time through, and I regret it. If you don't trigger Albel's event, you can still get him and Nel later, PLUS a chance at two more battle trophies.

If you don't do anything further with Roger on the scavenger hunt and just go through the game as normal, then you'll end up with Nel as your first extra character and you will have a chance to pick up Albel later plus 2 more battle trophies.

If you do the scene with Albel at the Peterny inn, Albel will be your first extra, and you will have a chance to pick up Nel later.

If you don't do anything, then Nel will be your first character. Near the end of the game when you return to Elicoor II you'll have a chance to fight Albel again to recruit him as your final party member. This is where you can get a battle trophy for defeating him with items only (pretty easy with 4 shots from ES Hybrid Explosives, 2500 MP damage at base price of 547 fol). After you defeat him you will be given the option of recruiting him. If you want the last Albel battle trophy than say "No" and wait until you return to Elicoor II again at the end of the game to fight him a third time. Beat him with items again and you will have the final Albel trophy, and Albel will force his way into your party as the last member. But remember, if you do the scene at the inn with Albel, you will never have the chance to fight him when you return to Elicoor and get these trophies.

Either way, you can still get Albel and Nel. If you're going for trophies, then I don't recommend you do the scene with Albel.

Another thing to remember is: If you do do the inn scene and get Albel first, then you have to answer Nel's question correctly at the end of the game to get her in your party. If you choose the wrong answer choice, you'll lose your chance to get her.

If you're going for Nel as your final party member, upon your return to Elicoor and Aquaria at the end make sure you select:

"There's no time for that right now" or something along the lines of that sentence.