Do you have any issues with the lighter leaking while you're applying vacuum? Just curious. I have a commercial-style chamber vac sealer and I'm forever sealing stuff up for camping & hiking! Very handy thing to have, for sure.
I haven't had any issues with leaking. Once the bags are sealed, the plastic "wraps" quite tightly around the trigger, so it actually "locks" it in place.
Without a vacuum sealing device, you can achieve close to the same result with an appropriate sized zip lock bag, perhaps double sealing it with tape....I don't recall a zip lock failing on me.
Yes you can, and this is what I have done in the past, however I notice that after a bit of use the ziplocks tend to get small punctures. Ziplocks do have the advantage that you can open and close them; but I like the fact these stay sealed - it means I can tell if anyone (eg kids) have been playing with fire !