Not silly questions at all.
No, not all manual trannies can be towed. Generally speaking, the answer is no.
Why would you want to tow something that can be towed 4 down on a dolly?
I say this because I now tow 4 down and previously had a dolly with a FW drive vehicle on it. If you carefully analyze the costs of a good tow dolly VS. 4 down, they are pretty close.
Even with a dolly, you still need aux. lighting on the toad. Most states have a limit on how far a towed object can protrude behind your vehicle without lighting.
Also, you do need brakes on the dolly. I know many will say they aren't needed, but most states require braking devices on towed devices over 1500-2000 lbs. (That means tow dolly (around 5-600 lbs) and vehicle (around 2-3000 lbs.)
Take into account the weight of the dolly AND the toad for your total towed weight. It does affect your fuel consumption. A 4 down toad is shorter in length as well as lighter.
Good Luck.