Thanks for leaving comments and words of encouragement!
Well, pod-mounted rockets would make more sense anyway; who in their right mind exposes high-explosive warheads to the heat of atmospheric entry?
I find this whole " I want to get it done but I don't want to get it done " thing to be a natural part of the creative process, so don't worry about it. Sooner or later the urge to create overcomes the shackles we hold ourselves back with, and amazing stuff happens. Until we'd rather stare into empty space again.
Oh, and about the undercarriage: Imagine if you had to also make it functional; able to collapse and extend to travel and landing positions, all the while conforming to a videogame's arbitrary rules (ex; "You see player, you might not think these parts collide mid-movement, but my code tells me to get them stuck half-open anyway.") That's what I was having fun with. Now they work but look wrong. Rebuilding time!
I see that you get me! But enough is enough - no more staring into empty space!
Don't get me started on making it functional. I spent probably too much time inspecting photos of the undercarriage I found online and can't figure out how it's supposed to retract into the housing. I thought I knew, but yesterday I realised that the part I thought made it more or less feasible is in the wrong place; I'll just do my best to make it sturdy enough to support the model and look like the solution on the original (which is a bit tough due to structural differences between the papercraft template I've used and the original kit) and won't bother with it any more. I. WILL. NOT. BOTHER. WITH. IT. I need to tell this myself to make it real.
About the rockets being 'exposed', especially in the context you mentioned, that's also something that's hard to explain - I mean, they probably look cool, but it makes so much more sense to protect them, especially that the "tech" is there - most (I think apart from the Xiphhon and Storm Bird) space Marine flyers use rocket pods.
Cheers honoured battle-brother!
Welcome to this side of the 2020!
Happy to hear you're still going with this project. Definitely go for the HBs. Rockets can always be added later and it even fits the setting that old tech (and Thunderhawk is definitely that) gets built over with newer additions. Often not entirely proper or matching but who cares as long as they are properly blessed 
Cheers, my fellow countryman!
I might magnetise the rocket pods. The entire craft, with the numerous alterations, is heresy, but it makes sense considering the fluff for my Crusade, being stranded on a forge world and being forced to make do with limited resources.
The thunderhawk project seems like a complicated and a long project, If you feel like painting something else for a while do that, a few weeks here and there doesn't matter the way I see it, this project is a once in a life time thing that few others on the planet can do and probably nobody else will do.
its better to spend a few weeks painting other sthings and recuperate yourself mentally than burning yourself out wih spending all your hobby time with cutting and gluing plasticard for this behemoth of a project.
You're right there! Who'd have thought that pursuing hobby goals involves so much planning, eh?
Painting is 'better' in the sense that it gives an almost instant sense of accomplishment. You can paint a model in 1-2 hours and see actual progress; with a project this big, it's not that simple. As I said, I might pick my brush up in the near future - right now I want to use the momentum to my advantage and do my best to get the Thunderhawk ready for priming.