beaner: a good way to make a humidified fruit chamber for you.
take a rubbermaid or likewise bin, that light can get through the top is preferable. it will need light. line the bottom with an inch of perlite to get right amount, take it out, soak it and drain excess water out, put it back in the bottom and flatten it out. use an air pump to run a hose inside, where u should have a little cup of water with a bit of hydrogen peroxide in it, bubble that to produce air for fruits. if u can have a couple small holes above the wet perlite but below your cakes co2 can escape. im assuming you'll sit them on foil bake pan inside the container. that should keep your humidity up.
as for innoc. temps, 86 is optimal for fast growth. growing at room temp will just slow down the process. excessive water will also slow down the process--which is why vermiculite is in about every recipe for mycellium.
a good method to keep growing is to break up the cakes after they are colonized and put them in foil cook pans, and make a case layer on top with some pasturized peat moss and perlite that is damp. keeping this layer slightly alkaline will produce more fruits. u can also lightly mist this layer to ensure fruiting in early stages. try not to get the mycellium wet.
in terms of easiest to contaminate, its easiest to do so in jar stage, less likely while your casing sits in dark, and least likely while fruiting.
you can always innoc 1 extra jar to break up and innoc all your next jars.
your process should go something like this. innoc, set in dark til colonized. break up and make case layer, set back in dark for 3-5 days to let roping form. then, into fruiting chamber, fruit once, pluck, twice, pluck, thrice, pluck, then use spent casing to make new jars.
hope some of that made sense.