Two days of fighting and I finally uploaded the new arduino firmware. Now you can choose the temperature table in Configuration.h as Marlin. The solution wasn't as elegant as Marlin (it's way beyond my mechanical engineering programming skills), but it works!
So you can try it!
Let's talk about your problems:
Temperature: remember you are not controlling anything with this and the margins are very wide so you don't need a very accurate temperature sensor (+-5ºC will be fine). To select my table, I tried some tables against a reference. What was my reference? A can full of boiling water 
! But I did this because I was testing the code. A more practical way to do this is to use the printer itself. Assemble everything, then set the bed/hotend temperature to a fixed value and check the if Safety Printer's sensor is reading the same value. Obviously, by doing this, you are assuming your printer is working fine.
Flame detector: Mine modules have the same problem. In this case the only workaround solution is to test then once in a while until whe find a better solution for this.
Smoke sensor: I checked your sensor specifications here: https://www.smartwares.eu/en-gb/smartwares-products/fire-safety/smoke-alarms/smartwares-10-044-62-smoke-alarm-rm250-10.044.62 and I think that this is not a good choice. This module is a standalone one and it don't have anykind of connectivity to other devices. Of coarse you can modify it but, in this case you can produce some problem there. IMO you should buy a new one (simpler wired one).