Well, my freak out about doing heroic Paragons for the first time was completely unnecessary. The merge guild's team were totally in control the whole time and since everybody except me knew what to do, it was easy.
I would have to say my heroic Blackfuse freak out was probably warranted, but I didn't do too badly at all - died on the first go (after someone else on the floor did, so they couldn't rez me), wiped on the second (slow getting up on the pipe and couldn't DPS wave #6 in time) and killed it the third, although I died right at the end when we were DPSing the boss instead of being on the belt (I had no idea what was going on on the floor, since up until this point I'd been pretty much permanently on the belt).
I'm pretty happy overall with my performance - the other hunter died once in the third Blackfuse attempt, so I felt better about falling off the pipe once in that fight. Plus, I managed to scrape top DPS on Thok (I realise that fight is totally built for hunters, but considering their strat involves 1 tank, 2 heal and burst DPS to get Thok down as the third door opens, I feel like I made a significant contribution...).
Unfortunately I didn't get to do Garrosh - they were taking another newbie through and didn't want a second - but at least I had fun raiding with them. Plus, there was the added bonus of having the entire rest of the week off from raiding - so efficient!