mdilthey wrote:1) The use of technic frames inside larger ships without sacrificing an interior.
TECHNIC frames (and TECHNIC in general) are bit of a hard subject. They can be as complicated as you want and as hard to build as you want but if you just want something robust and simple, it's not hard. Like DavidP wrote, TECHNIC bricks in horizontal parts and beams in vertical parts. Only specific thing that you need to remember is to place the beams in such a place that they are in the same line as studs (normally TECHNIC bricks' holes are in between two studs).
If you specifically want to build interior, I would suggest first building interior with as many sides as you can. Then alter the design in such a way that you can fit robust frame around it. After that, you can either start building SHIP around it or try to fit it into already existing SHIP.
mdilthey wrote:2) The ability to know exactly what to buy plenty of on Bricklink to expand my model building ability, without wasting money on stuff I don't need.
This one really comes down to one question: What is your building style? Even in a specific "sub-genre" like SHIP building, there is a lot of ways to create things. For example, some people want to create SHIP's outer skin aka "skin" out of plates and tiles while other prefers bricks. First person would invest heavily on plates and tiles (mostly for tiles, I think) while the second invests in to bricks.
If you are not sure about your building style, I suggest that you just buy small amounts of different bricks and experience with them.
mdilthey wrote:3) A sorted collection. I'm still on Big Bins.
Sorted collection is important thing in my mind. Even thought it is harder to maintain, when you want to build something specific, sorted collection allows you to find bricks very easily.
Oh and I suggest that you don't sort by color as your first sorting method. Sorting by color is easy method to divide the collection to smaller chucks but have you thought about how usable it is? Trying to find small black piece among other black pieces is very annoying task and quickly tears your eyes... I personally have sorted my collection with either form or function. That means that if I have group of similar pieces (like arches), I keep them in same bag. This might work for you too but I am not sure. Experience and think about it
mdilthey wrote:4) LDraw, if it's even necessary to be a good builder. I haven't explored it at all.
LDraw (or more modern MLCAD) and the LEGO company's own LEGO Digital Designer are good tools that can help you a lot. They are not necessery tools but still, they might be just the thing for you to allow experiencing more. If you wish to try them, I would encourage you to start using LDD because it's much more user friendly than LDraw and MLCAD. With the "LEGO Universe" mode, you can use very large palette of bricks (althought you can't order the complete set..).
I hope this helps!