Tell us about yourself!
If it's staying on all the time then something's done up wrong. It could just be some sensors turn on for a few mins when initially powered up before turning off and waiting for the light level to drop enough to turn on
Hire a licensed electrician
It could be wired wrong
Call a licenced electrican
I am a Mechanical and Electrical engineer. It is just not something that people that are unknowing can really safely build. Yes his ratings are ok but if someone builds this and does not know what the C rating is and uses too small of a battery. You know something about it the hobby RC community does as well but someone that is not involved in RC more than likely has no idea what those ratings mean. There are plenty of batteries out there that do not have a high enough rating to run this and then you do have exploding batteries. Even major manufacturers have problems with it look at the Samsung galaxy note 7, they banned them from going on airplanes because they blew up unannounced.
Yes but even the E cig batteries blow up and the resistance on those coils is much higher than the graphite in this project. NiCd or lead acid battery chemistry would be much much safer for this project than LiPo. The lipo have a very small window for charge and discharge where they are happy the rest you will get a visit from some very angry pixies if not right away after a few uses.
short circuiting a Lithium battery in this way is a VERY BAD idea do a google search for short circuiting lithium polymer batteries. There is serious potential for this to literally explode in your hand.
No metal, a 40W co2 laser can cut 3/8" polycarb or acrylic with a couple passes
you would need closer to a 30W CO2 laser to do that