Answers are yes, yes and yes.
Natural gas and LP internal combustion engines are the best to woodhgas convert. Eg; Ford/Onans, Kubota DG972 3 cylinders and 4 cylinder GM industrials versus the earlier gasoline B &S's, Honda, Kohlers and Generacs at both of the All Power Labs and Victory Gasworks shops.
Wood chunk size is best matched to the gasifier internal sizing. Gasifier size best matched to the actual horsepower you are asking the engine to produce. Horsepower size range of engine matched to your genhead demanded electrical avarge and peak demand needs. And that in turn will be limited in how much wood supply you Actually Can produced chunked up usable, the deepness of your pocket book to set up or purchase a system. And especially your patience and persistence in learning how to daily operate a system. Means you WILL have to work at it daily for fuel prepping, fuel stoking, condensates, soots and ash cleaning out. Actually much simpler and safer than old steam power . . . but after 60-70 years of being spoiled by easy turn key refined Dino fuels, and switched flip electrical grid most cannot make the transition back to personal daily energy production responsibility. Eg: cord wood bulk heating folk versus pour from a bag/flip a switch commercial wood pellet heating folk; and fuel oil furnace folk knowing/learning they NEED annual soot/burner head/nozzle and filter service versus the clueless "What? I Need any service, ever?!" electric Grid heating folk.
Your specific DYI answers to a useable woodgas fueled stationary system start here:
www.woodgas.nl read the MicroGasifer PDF for fuel matched sizing, ect.
Some decent YouTube videos seeded in the chatter/clutter out there too. Look for the posted up work of "foxridgecamping".
Smallest wood chunks I have ran were 1/2"x1/2". TOO SMALL. Right angle flat sided blocks suck. They face to face stack blocking gases flows pathways. Was much better as 1"x 2-3" sawn strips with at least two sides irregular hatchet chopped. Softwood better bigger. Hard woods better smaller.

Regards
Washington State Steve Unruh

I have started my gasifier and needed these dimension. I don't think I can use most of them because of my design but they give me what I need. My gasifier will be modifiable at the air intake and throat just below the reaction area. I have given it much thought and I think it would be nice to be able to change parts out for two reasons. Smaller throat for smaller motors and or in the hottest zone, one may need to change out the throat plate and screen. This info is helpful and I hope to have a few more details worked out so I can finish my layout. I will be posting photos and plans here in the blog area at some point. Still welding on the basics for now but I am getting near the final design.