is it possible to make a pot (marijuana) plant that you could grow and smoke, and possibly even sell?

It might be, I don't know because I've never tried, but making something that complicated is not something you want to start with if you're new to modding. First you should go through the basic object tutorials to learn object creation, preferably starting from recoloring and then moving on to meshing. But making a functional object like that with new interactions takes a lot more than meshing, especially with a completely new actions like smoking, would involve animations and interactions, which would be a whole another area. Definitely not for beginners .

And, please, don't make the same post in multiple threads.

sorry and thanks

You would be best to start by cloning the Opium Poppy from Seasons. Also, be sure to get some plant grow lamps, I forget where they were from.
That gave me an idea. There is some medical equipment, like a syringe and such, already made. And I know I have seen some tie-dye clothes. If someone would mesh up a bong, we could use the pot plant and all that stuff to make a dope fiend career!
Of course, to make it realistic, maybe we need to add a Narc specialty to the Law Enforcement career, and probably a dope dealer career, after all, without pushers what good are addicts?
Now Inge made a jail once, we could make a part of the dope fiend and drug pusher careers a stint in the slammer, just like in real life!
And with all the cars in the game, someone could make a lowrider gangmobile so we could have drive-by shootings in the 'hood.
Boy, this is just the kind of realistic stuff that would make the game so good, like real life, not some lovely little escape from the rat race.
Speaking of Rats, if we took Pets and th

Already a few refeer themed objects exist, but they are mainly in the adult sister site...

I was going to mention that this sort of thing is not mts2 material. Illegal drugs go on that other site. Getting help with modding is fine, but you'll find what has been made already over there.

What is the adult sister site?

The name of the site is Sexy Sims 2. As for the rest, you will have to figure that out on your own, as mts2 is not adult oriented.

locking thread as it's now offtopic