Sorry, but if you want help from Feral Heart, we would really like it if you asked on their own forums. There is a reason why we have separate forums for these two games, because they aren't like each other, at all.
As for your questions about tutorials and such, I'm afraid Google is your Best friend, as they like to say.
And yes, we use Open GL as one our our two rendering systems, along with Direct.
As for making LM for Ubuntu, I'm afraid that's very low on our priority list, as we are in the middle of creating a Revamp, or \The\ Revamp for LM. It's very time consuming as is, let alone having to re code LM for Ubuntu. We don't even have LM for mac, let alone Ubuntu.
Sorry Hun!