With the upcoming Shuttle PvP queue, it would be a good idea for the devs to review certain shuttles (mostly Romulan) for consistency and balance. Note: all shuttle stats were taken from HOLODECK, as I didn't have the Scorpion available in Tribble.
The Singularity Power (and power penalty) for Romulan Shuttles is inconsistently applied. When Legacy of Romulus was released, we were told the 160-point power pool (compared to the normal 200-point pool) was to compensate for every warbird having the set of Singularity Powers and a Battle Cloak. When it comes to the shuttles, however, we get a mishmash of cloaks, power levels, and UI issues, listed below.
Scorpion: Battle Cloak, Weapon Overload, 160-point power pool. UI is missing the Singularity Core interface, so the power has to be slotted and it's difficult to tell what charge level the core has achieved before using the power.
Kestrel: Cloak, Quantum Absorption, 160-point power pool. Again, no Singularity Core UI, so charge level is hidden.
Commander's Gig: Cloak, Singularity Jump, 200-point power pool. Singularity Core UI is present.
Tiercel Shuttle: (Not that I expect anyone to try to PvP in this, but...): Battle Cloak, no Singularity Power, 200-point power pool. No Singularity Core UI, but this would be expected.
So, we have two shuttles with a 200-point pool, and two with a 160-point pool. One of the 160s gets the full benefits of the singularity core: the singularity power and a battle cloak. One 160 gets a power and a regular cloak. One 200 gets a power and a regular cloak, and the other gets a battle cloak but no power. For comparison, the Toron shuttle gets a 200-point pool, a regular cloak, and a power.
Singularity powers can be used more frequently than the inbuilt powers on shuttles (as little as roughly every 32 seconds, with the right gear, firing only at charge level one, and bit of luck), which would justify somewhat the reduced power pool. However, I don't feel this justifies the full penalty that all warbirds pay for 5 powers and a battle cloak.
My suggested fix would be this: reduce the total power pool by 20 points each for a singularity power or a battle cloak. The Tiercel would have a 180-point pool (45 in each stat) because it has a battle cloak; the Kestrel and Commander's Gig would have 180-point pools because they each have one singularity power but not a battle cloak; the Scorpion would have a 160-point pool because it has both a singularity power and a battle cloak. I think this would be a fair trade-off of abilities.
That being said, the Klingon Toron shuttle gets a free cloak (but is otherwise identical to the Danube) and the Klingo To'duj gets a free battle cloak when compared to the Federation Peregrine, again without penalty, so it's not necessarily true that any of the Romulan shuttles need a penalty applied for balance.
The last shuttle I would suggest looking at for rebalancing would be the Tal'Kyr Support Craft. This shuttle has an abysmal turn rate and inertia, and while it enjoys two bridge officer seats as well as an inbuilt power, the seats are science only, and the SIF transfer appears underpowered (although this may be due to poor tooltips; as near as I can tell, at 114 aux it's healing roughly 1600 hull over 10 seconds, which is less than 10% of my shuttle's health). It has a short cooldown, but it's a channelled effect that presumably requires the target to stay within range, and has only a small effect; a shuttle would have to devote a lot of time to have any significant impact on another shuttle's health, much less a full ship. This shuttle is just begging for some extra love, either in its inbuilt heal or its maneuverability (it can't heal what it can't keep up with), or both. As it is, practically any two-seat shuttle would make a more effective support ship than the Tal'Kyr does.