Where to start....based on what youve said, you have no business using any AAS at this point, for a few reasons. First, you just started back to eating and lifting. This is not the time to add in AAS. I know the temptation is strong, as Im fighting it as we speak, but its better to get back into a consistent routine of lifting and eating properly before adding any AAS. Ok, I just reread your post about it being a TWO YEAR break. You really shouldnt be using anything at all, other than a protein supplement and multivitamin.
Secondly, the questions you asked about the products you are using show that zero, or almost zero, research has been done on them. Thats not a good thing. Research comes first, buying comes much later down the road.
Third, based on your goals of "long, lean muscles," you dont need to use any AAS anyway. Long, lean muscles is some selling bullsh*t that you hear about on tv. You get long, lean muscles IF YOURE BORN WITH THEM! You cant change the length of your muscle bellies. The only thing you can change is their size and strength.
What you are probably referring to is the desire to lose fat. Thats fairly easy and can be done without AAS of any kind. Some modifications to diet and exercise and you'd make great progress. Fat loss will bring out the muscles that you have. Oh, and trying to lose fat without lifting is pointless.
I dont mean to sound like an assh*le, but people think of AAS as a magic bullet. Its not. Its a tool to use after training, nutrition and recovery are dialed in. And even then, only after a lot of research is done. Its better to hold off on using, rather than use something that you dont know what it will do to you.
Now to answer your specific questions...
Clen: 2 weeks on, 2 weeks off is fine.
Primo: I would advise against using it. But if you choose to use it, then be smart. 200mg/wk should be plenty for a woman. And no, you shouldnt have to worry about virilization from it. Anavar is another "female-friendly" compound. Oh, and using primo for only 3 weeks is a waste of good product (assuming its even real).
T3/T4: The difference between T3 and T4 has nothing to do with one supposedly being natural and the other synthetic. Both are naturally produced in your own body. A portion of T4 is converted to T3 in your body (around 25% IIRC). T3 is a much better enhancer of metabolism. Pretty much any pill you take is sythetic, even if the original source is natural (ie. produced naturally in your body). As for dosing of T4, probably 75-100mcg per day. IMO, using T4 for dieting purposes is rather useless. T3 is a much better product for that.
If you want help on your diet and training, Im more than happy to help out with that.