I know pulping junk mail and turning them into briquettes for heating is actually a proven idea. I wonder about the efficiency however, aka how much heat am I getting for the time I invest? My time is worth money, so if the return on that time doesn't yield properly it's not worth it. I also only have electric heat but it's something I would try if I had a stove, which I plan on putting in The garage in the future. Of course buying sawdust cuts into the savings, there has to be a free source somewhere I you look around. As for me I religiously recycle, so it either goes off to be recycled or shredded and thrown in the
compost pile.
Are you talking bamboo timber to burn? If so I'd almost say it would be a waste of time. Building material would be worth a try but you'd have to alter techniques to use it. Either way it can't hurt to give it a try, and you already purchased seed so why not. I'm weighing the option myself but I don't want a 40-50ft tall stand of timber-worthy bamboo in my yard. Probably gonna go with a smaller clumping bamboo to use for garden stakes.
Most corn after harvest is turned to silage or dumped back onto the field to compost in place. Basically they take the leftovers, ferment it, then feed it back to livestock. Probably one of the more "permaculture" things I've seen done by big agricultural so I'm cool with it. Most around here use a no-till method so they leave the leftovers to rot back into the soil. I can't see anything from the grass family (corn and bamboo) being a heat source worth the time. Yeah, it'll burn, but it'll burn quick, probably not produce much heat, and would leave behind a ton of ash which you then have to find a use for.
In summation, junk mail for heat is probably the only idea I would personally pursue. If you want to grow bamboo for building material go for it. Been done for thousands of years and it works. Really what do you have to lose by trying it? Wouldn't even waste my time burning corn silage, let it feed a cow or the soil. The sheer amount you would need would make it impractical and the results would be less than stellar