Belgian Tripel Fermentation Problems/questions

OK. So my Tripel is stuck at 1.022, from the OG of 1.070 (used 10 lbs of Pilsen LME and .4 lbs of light DME). These numbers seem horrible and way off the mark, but it is what it is at the moment. It had two weeks in primary and almost four in the secondary. The gravity readings have been the same for 2 weeks now, so I feel the need to just bottle it and see what happens. I am planning to use mostly champagne bottles and was thinking about adding some more yeast before bottling. My question is if I add more yeast with my stupidly high FG and the bottling sugar will I risk having some sweet bottle bombs? Or will the bottles just need longer to mellow? Thanks for the help in advance.

Sorry, forgot to mention what kind of yeast I used/would like to use for bottling: Wyeast 3787 Trappist High Gravity.

I think that your fermentation is finished. Malt extract finishes at a higher FG than all grain or if you were to supplement some sugar for extract. I don't believe that you need more yeast to properly carb up but it wouldn't hurt anything if you do. Definatly let the bottles sit and mellow.