That's a subjective question so I would advise that you download the Premiere Pro trial and give it a go...
That is going to be a problem.
Premiere trial does not approve of most HD stuff.
My CS5/AVCHD 1st Impressions http://forums.adobe.com/thread/652694?tstart=0 includes discussion of down-converting to AVI to then go to Encore for a DVD
I don't do PAL, so have no idea if or how well PPro does at conversion
I ordered CS5 and will try some tests with the straight encoder. But I suspect that AviSynth is still useful (http://avisynth.org/mediawiki/Main_Page). It was the best converter I found so far. It is a bit tricky to use, but it does a great job.