Not a cicchetti crawl place per say, but in the Rialto Bridge area when walking to Piazzale Roma, on the side of the Grand Canal with the market, is an out of the way place named Pane Vino e San Daniele located on Calle dei Botteri, San Polo. Definitely a small local place, good food, good house wine, and not expensive at all.
On the other side of the canal, also in the Rialto Bridge area, is Trattoria Da Marco Valla Fava. It's located on Calle Stagneri. It is definitely an upscale place that has some of the best sea food ever!! Try to eat inside rather than outside. The place has been around at least 50 years so they must be doing it right, and we've never found it to be overly "touristed".
You should be able to check them out on the internet, and Google Maps street view is a great tool to locate these places and "walk" to them ahead of time.
Yes, it is possible to tour Murano and Burano in one day, on your own, using public vaporetti. Just get an early start to beat the crowds.
If you are on Murano at lunch time, try Ristorante dalla Mora on Fondamenta Daniel Manin. Lots of locals eat there.