I was climbing there a month ago in Launceston. Launceston gorge has TONS of trad lines to keep you entertained. They're short but access is easy, the town is cool, and its a pretty area. Noone seems to really use MP there. There's a forum specifically for this state; I can't remember the site. AUS uses thecrag.com but Tasmania doesn't get so much attention there. Talk to Ian Ferrier, admin@mountainbiketasmania.com.au, and he'll help you out.
Even if you'll be in Hobart, he might know some folks
In terms of finding partners, posting in the Facebook group "Climbers Club of Tasmania" is a good way to start. Be sure to post your travel dates, what gear you have and roughly what grades you are willing to lead/second for best response :)