@marcb0t thanks for the comments! Yeah I love melodies and motif themes. A lot of these songs I imagine as being from "seperate games" but if I had other songs from one of those games, I would probably make arrangements of the melodies. I did do that actually for the "Jason Valor theme", remixing it in "Poisoned Heart." I imagined it as a version where you fight Jason Valor himself, but probably towards the end of the game or something.
Anyway, I still plan on getting into famitracker. I have the program downloaded, I just haven't really gotten around to it yet. At least right now it looks a little complicated, but I think I know how it generally works, I once used a similar program that ran on a gameboy emulator, anyway. Mostly I just have a pretty comfortable set up for making songs, so I would have to transition to famitracker slowly. It does seem a little bit daunting, but I'm also excited because I'm pretty sure I can get more variety of sounds from it, and do tricks like portamentos and whatnot. It looks like there's a good amount of control over them.
My pleasure, and yes I'm very much the same, and have ideas for whole albums that have related motif themes, and so forth. Not for every song per say, but most songs, like in a John Williams soundtrack or something. Obviously the Cantina tune on the Star Wars soundtrack does not sound like the main theme at all, but a lot of the movements share a basic theme or subtle background chords and movements. Yes, I admire that kind of musical style.
Famitracker was never daunting to me. It was very thrilling and exciting with each new thing I learned. But I dive right into things first, and when I get stuck, then I finally decide to read the manual. 
But everyone's different. Yes, you will get very precise portamento, very easy to implement as well, actually. Same as with vibrato. Can start, stop, and alter intensity right down to the very frame per note. That's why I really like trackers for chiptune making. You can also do lots of cool things with arpeggios, tremolo, and have authentic usage of the 1-bit DPCM sample channel. You cannot find a better tracker for NES... that I have seen. (Somebody correct me if I'm wrong 
)
But yeah, take your time, though, no need to rush into things. Your music sounds good just as it is. I enjoy it. And if you'd ever like someone to work with on a Famitracker tune, then I'd be willing to.
Take care,
marcb0t 3.0 --- yo!