Firstly, I wouldn't bother with a day trip to Venice when on a motorcycling holiday. The roads & scenery around the lake are far too good. Go to Venice on a cheap flight for a weekend if you want to see it.
Places to visit: for me the northern end of the lake is the best. Spectacular scenery and some excellent roads that climb up the steep valleys.
Of the towns around the lake, my favourite is Malcesine. Lots of narrow alleyways where you can find little bars and restaurants. If you fancy an afternoon or morning off the bike then take a cable car to the top of Monte Baldo.
On the opposite side of the lake is Limone. A charming little town. It even has a beach should you fancy a dip in the lake. We used the excellent passenger ferries to get between towns.
The mountains to the north of the lake are fabulous. I took the SS241 from Riva to Molveno and further north, then back down via Madonna di Campligio. My son seemed a bit worried on some of the single track roads with no barriers and a big drop off. I loved it.
I can't really recommend a hotel as we used a cheapie from Expedia on the outskirts of Limone. It was okay but quite a walk down a steep route into the town centre. Hotel Limonaia. Of course, the height above the lake meant it had superb views. The other place I've stayed is Torbole. A very small town with a few hotels and a nice atmosphere as it is popular with a younger, watersports crowd. That was several years ago so the hotel we used may not be of the same standard.
Lake Garda is one of my favourite places. If I returned I think I would bite the bullet and cough up for a decent hotel in central Malcesine.