lens choices, help, opinion

I am really starting to get into photography, shoot with Canon Ti(but plan on EOS 3 after christmas) and have 100-400 IS, 50 1.8mk1, and the 28-90 that came with my body, now am looking at another len(es) and am contimplating going w/ a 24or 28 prime and a 70-200f4, or going with 24(28)-70(80) 2.8 zoom and 70-200, what are your opinions on primes on the lower end, or would I really even notice a difference. i shoot mostly nature, macro, portraits etc, but have never and probably won't shoot architecture, unless paid. Any opinions on those or others that I may have not thought of, thank you

My thinking, with the coverage you already have in place, is basically 'Why do you need more?' That's the question you need to answer, to identify your needs.

A wide angle Prime might, or might not, offer sharpness and aperture advantages as compared to the 28-90 zoom. As these tend to be pricey, it bears some serious consideration.

The same could be said for the 70-200/4. With the 100-400 IS already in place, it seems like needless duplication - unless the f/4 capability is an advantage you need?

With what you already have in place, and your shooting priorities - I would be looking into Macro lenses and Portrait-length Primes.

A dedicated flat-field Macro lens, such as a 50 Macro, offers many creative possibilities. These are the ones which have, for example, a 2" depth of field at a close-focus distance of 8-10" - which is just right for getting a single Flower in very sharp focus, while everything else is just so much colorful blurred background. Then at the other end of the focusing scale, these same lenses are often superb for Landscape shots.

A 'Portrait-length' Prime can economically offer advantages over a zoom used at the same length - most notably in wider apertures, and in some cases, sharpness. There are also 'soft focus' lenses, if you like that effect. You should study what lengths you are currently using on the zooms for portraiture, to decide if you should first target getting an 85mm, 100mm, or 135mm. Don't be surprised if you eventually have all three - each with their advantages and disadvantages.