LBP is very easy to use, and everyone takes it. The problem is withdrawing money from the ATM with the currency issues. The majority of restaurants and bars will give you the total bill in LBP or USD, and you just decide what to pay with. I always preferred paying in LBP as I think the conversion rate isn't as good as the money exchange place I used. I stayed at the 4 points, and there is a mall next door with a money exchange that had a set exchange rate, so I didnt need to negotiate with them and didnt feel like I was getting a foreigner rate. I just exchanged $200 USD at a time, and then kept an additional $200 USD on me, and the rest in my hotel safe. Outside of the airport duty free, I didn't find anyone who accepted Amex, just Visa.

Every uber/taxi driver would be more than happy to take you to Balbaak. Uber quotes $60 one way from Beirut, in which the driver keeps 75% I believe. Finding one who will do it for $100 USD off app should be easy, just make sure you do a normal ride with them first so you have a record of the driver just in case something fishy happens. I'm not saying there is even a small chance something could happen, but I always like to play it safe. I took a screen shot of my driver and car info and sent it to my family group chat. Also make sure the car is decent, as you will be driving through mountainous roads. If you like him, you can also ask him to drive you to other areas outside of Beirut. If it bothers you, you can make the point that he won't smoke in the car if you hire him.