Great job! Just picked one up from my local hobby store and can’t wait to build it.
TOS (The Original Series) canon was that the warp nacelles created a warp field of varying intensity. The Impulse engines than provided thrust to move you places.
So, fan-based canon is that the shuttles can generate warp fields, and the pulse engines get them from place to place. (Which allows them to travel great distances to advance plot lines.) The Shuttles are also SSTO (Single Stage To Orbit) vehicles, so they need large Impulse engines to achieve that sort of manoverability. (Which also advances plot lines.)
The the various series, they honor that canon, by having ever larger impulse engines on major space craft. And the Shuttles all are capable of long range travel, leter to include enough power to support Transporters.
TOS is imprecise about whether Shuttles are armed or nt (they are in later series as a matter of course).
As an interesting bit of trivia, the prop was ot available until Episode 5 of TOS, which is why they inveted the Transporter.
A quick diorama build until my other one is 100% finished.
