This is all IMHO, so don't think I'm a Nazi. :lol:
Perish the though, we all have opinons

As for your ideas first the ones I prefer mine.
Roll bar, too angled
torp tubes on the engines - can imagine an engineering no no.
Ideas that have merrit but would have to think about.
streamlining the aft section - But I don't want a cone shape on the back. I want the lines to resemble an updated Miranda not a Sov. A happy medium will be hard but variations of the design can be made by others after release.
Phasers on nacelle pylons - Though I'm happy with the current pylons.
I'm planning to put the deflector on the roll bar with torp tubes either side.
Please keep the ideas coming it helps with things I may have missed, but I have to be the judge at the end of the day since there is no reference to follow.