questions about transformers

1. Is there a limit to how big or small a transformer can be?

2.can a transformer of any size mimic a vehicle or machine of any size? Like for example let’s take a transformer that is undercover as a roomba were to scan a nuclear submarine for the military could it change with no problems? Where does all the mass go or come from when they transform?

3.does a transformer have limitations based on what they are disguised as? For example let’s say the autobots found an energon deposit and need to go on an underwater mission can they survive underwater no problem or does Optimus have to scan an underwater vehicle to survive

4.since in most versions on tv I’ve seen usually have the autobots show up with no tools or equipment to work with and earth technology is so primitive how do they build their advanced technology where do they even get the materials like for example let’s say they landed in the 1950s and Optimus prime turned into a 1950s ford truck how would they build their base

5. How would they blend in during a time period with either no vehicles or with no machines like ancient Egypt because the only way I can imagine them blending in in say the industrial revolution or the Wild West is by disguising as trains but that’s risky and raises questions if a train vanishes or drives around by itself with or without tracks