I tried to adhere my fondant this time without a fresh coating of BC, and just misting the crumb coat. It seems to have worked fine, but I have air bubbles in a few places.

What is the best way to fix them? I do not have access to a hypodermic needle to inject any liquid under the bubbles. If I just pierce them with a tiny needle, will they go away without a 'glue'?

just pierce them with a tiny needle

Also, pierce at an angle not straight in, and smooth from the opposite side to release the air.

pierce them with a pin at an angle (this way, you can press it closed, rub a little crisco on it, no one will know). Work the air out, beginning at the outside of the bubble, pushing towards the center, gently pressing the fondant against the butter cream as you go. I use non crusting butter cream under fondant so that it will remain tacky and the fondant will re-adhere in these situations. I don't normally get air pockets, but if I do, I will leave the pinhole open until I absolutely need to close it, just in case there's more air in there that needs to work its way out.

Things I do so I don't get air pockets to begin with:

- Press down on the cake as I am Stacking layers.
- Don't place layers straight down on each other, if your filling is lower than your dam, this can trap air between layers. I place one edge of a layer on the edge of the layer below and gently bend it as I press across and down towards the far edge of the cake, forcing the air out as I go.
- don't beat too much air into fillings/icings
- After crumb coating, I make a dowel hole straight down the center of the cake to give air a route to escape.
- let the cake settle overnight before applying fondant.
- After applying fondant, poke through to the center dowel hole I'd made to reopen the air's escape route (this is only possible if you'll eventually be placing something over this hole, like a flower or decoration, or another layer, in which case, you just refill the hole with a support dowel.
- Don't decorate the cake until the day after you've covered it with fondant. This will allow time for any such issues (bubbles, bulge, sag, etc) to surface and be dealt with. If they surface under a pile of decorations and lustre dusts, you may have a heck of a time fixing things without making a mess of everything.