Yes, they have been made.
No.
Yes If it is .38 special, this is correct. There are other types of .38 caliber other than .38 special, however.
To the best of my knowledge, no manufacturer has even made a .38 Special rifle, so no. .38 Special can be used in .357 Magnum revolvers, but that's because revolvers don't have a headspaced chamber - this cannot be done in firearms which have a headspaced chamber (as rifles typically do).
50-300 usd
38 special
The only company making a rifle in 38-40 would be cimarron,a Italian maker of cowboy action rifles.These are well made reproduction rifles of Winchester design.
Yes. The 44 magnum can fire 44 special ammo in the same way a .357 magnum can use .38 Special.
Depending on who makes it, they can range from 25-5000 USD.
In a lever action rifle? No, it's not recommended. .38 Special rounds are compatible with .357 revolvers because the cylinders aren't a formed chamber which requires proper headspacing. The .357 lever action rifle, however, does have a formed chamber designed specifically for the longer .357 Magnum cartridge. With a .38 Special round loaded into it, it won't achieve proper headspacing, causing a potentially catastrophic situation.
The .38 Special can fire .38 Special, or .38 Long Colt. It cannot fire the .38 S&W, which is fatter and shorter.
If you placed the shot right, then yes, it could. However, if I had to pick a round for that purpose, the .38 Special would not be it. If you're hunting wild hogs, or just trying to put down a domesticated one, you really need a rifle.