Bernd, I lived and owned a cabin in the Bella Coola Valley for a number of years in the '90s.
Grizzlies can be problematic anywhere in the valley bottom (i.e., from tidewater up to the Antnarko River at the bottom of the "Big Hill") but in particular when the salmon are running (pretty much spring through the fall months).
My favourite place by far for day and multi-day moutaineering adventures was the Noeick Meadows/Ape Lake Trail area which you access from the Nusatsum Forest Service Road (~ 20 km from tidewater then a ~ 15 km drive to the pass). Another spectacular place better for hiking than mountaineering is up on the plateau in Tweedmuir Park.
If you haven't seen it already, check out the following web site: http://www.bellacoola.ca/index.html. There's a couple of basic maps and some good information to get you started.
As for guides, there's so much to see and do and if time is limited I strongly urge you to spend some money and hook up with a local. I noticed on the web site referenced above that Doug Baker is now now guiding. I worked with Doug a few years back and recall him being a decent and talented fellow (Doug Baker, Box 313, Hagensborg, BC, V0T 1H0, Phone: 250-982-2537). Gary Shelton is also a fellow worth tracking down - he's a bit older than Doug but ran a hunting guide service so knows the mountains extremely well.
541075-BCoolaMap.pdf