Hullo... By way of introduction, I'm one of the fellows working on the Macross ships on RC Groups. I design my own aircraft, many of which have strange design features (swept-forward wings, canards, tipsails, flying wings, multiple motors, differential thrust/thrust-vector, etc.) and nearly all have proven to be at capable of reasonable controlled flight.
I've already flown a prototype SV-51, and now I'm working on a CAD design for a twin ducted-fan version, with working thrust-vector vanes. (See attached.) The SV-51 is quite similar to an F/A-18 Hornet, or Su-27, aerodynamics-wise. It's also 'cleaner' than other anime/Macross aircraft I've seen. The ducted fans do add some complexity and risk, but... Oh well.
The YF-19 could be a bit more difficult... I'm having a fuselage carved out of solid foam by a guy with a CNC machine, and plan built-up (and sheeted) balsawood wings. Stability is almost certainly not going to be an issue, what with the large cluster of fins towards the back. Also, the 20" YF-19 testbed has already proven that it has positive stablilty in yaw, and what appeared to be neutral stability in pitch. The biggest problem is getting the center of gravity where it needs to be. The weight distribution of the design is pretty bad, a lot of the airframe's mass is concentrated aft...
~Luke