I'm flying into BRU on LH from FRA at 8am on a Saturday to connect to an AA flight at 10am to the US.

Do I have to go through security or customs or immigration? If not, 2 hours seems plenty of time, given the size of the airport.

Are there any lounges I'd be able to use?

Anything I should know about this airport?

From Germany to Belgium you do not pass through customs. Both countries are in the Schengen system. If you are eligible to use lounges then yes, you can go to the BritishAirways lounge and have all the alcohol you want....

The airport consists of two long gate halls tied together at one end. this image does not begin to show the length of the halls:

http://www.brusselsairport.be/

The airport is very short on signs. When we arrived at the tip of one hall from MUC, we did not see a single sign to direct us to the main ticketing area to get tickets to continue to IAD.(remember, the LH-UA alliance cannot issue tickets for each other about half the time).

The airport personel seem to all do English very well, and we were escorted out the "in" door at customs to get our tickets at the UA counter.

Our international UA flight was at the end of the other hall. I think they have tried to make the airport seem as big as FRA.

The shared BMI(?) star alliance lounge was packed.

Do you mean tickets or boarding passes?

AA told me that all I have to do is walk over to the AA gate and pick up a boarding pass, that there's no need to go out of security to reach the AA ticket counter.

They are probably correct.

We had to go through the ticket counter as we had UpGrades on other cancelled flights the day before, going a different way, and the story gets a lot longer.

2 hours is enough time but you will need to go through customs and security again. Your arrival and departure terminal will be different as the new Schengen terminal is not the same as the LONGGGGG, older internatinal terminal. After going through customs the American Airlines flight will depart at the very end of the long terminal-a decent walk. All U.S. bound flights depart from this secure area and you will need a boarding pass to get pass securtiy that gatekeep this particular point. As a result I believe you will need to pick up your AA boarding pass at a transfer desk before reaching the gate. While I am not sure where their transfer desk is they certainly should have one since they have a good relation with Sabena, codesharing on many flights. Lastly, the terminal AA uses really lacks food and shopping outside of the main entrance and that is where the lounges are too (upstairs). Once you venture to your departure gate you are out of luck on any selection of food or goods.