I think this idea seems fairly reasonable. There are a few disagreements as to how exactly the cloaking device would work (notably with regards to shields), although whatever potential solution is eventually agreed upon could easily be explained in-universe.
One thing that came to mind while reading through this thread was the
Survivability Onion. Each layer of the onion is currently represented in ED (including the outermost layer "Don't be there in the first place" which isn't shown in the link) as follows:
- Don't be there in the first place - Solo/PG/Open gamemodes (I'm not going to talk about this, but I must specify that it is separate from the "Don't be seen" layer)
- Don't be seen - Silent running, heat management
- Don't be hit - Ship maneuvering, Point defences, ECMs, Chaff, Gimballed/Turreted weapons, etc...
- Don't be
penetrated damaged: Shields and related modules
- Don't be killed: Armour, HRPs, MRPs
Of all of these measures, the single most developed layer of the onion is "Don't be hit" with multiple outfitting options and specialized counters introduced through engineering (emmisive, dispersal, dazzle, drag munitions, TLB, etc...), followed by "Don't be damaged" with multiple outfitting options and several hard counters with engineering (reverb, feedback, and phasing) each of which require specialized weapons or builds. By comparison the final layer of the onion is relatively tame, the defensive aspect is a choice between hull and module protection while the offensive aspect is a choice between hull and internal/external module damage.
Now, compare each of these layers (ignore the "Don't be there in the first place" layer, FDev has said that they will never change it and I don't want to turn this into an argument about modes) to the "Don't be seen" layer. The other layers feature multiple choices on both the attacking and defending ends of the engagement, while "Don't be seen" consists of many outfitting choices on the end of the player trying not to be seen while the other end consists of a few learned skills and the simple non-choice of 'toggle night vision on'. Effectively, the "Don't be seen" layer of the survivability onion is so one-sided that it may as well not exist in ED, which is a shame since it has the potential to offer a large amount of gameplay.
As for the concerns behind stealth ramming, my thoughts are that a ship should not be able to use shields while cloaked, but deactivating the cloak SHOULD raise the shields to the level they were at when the cloak was activated. The sole exception to this rule would be when the cloak is deactivated due to incoming damage, meaning that:
1) The cloaked ship would not be able to ram a target while cloaked without taking a large amount of damage
2) Ramming a ship while cloaked insures that you are more venerable to incoming fire when your cloak drops
3) Damaging a cloaked ship (in any way) leaves the ship venerable to additional damage
4) If there is a delay between the cloak dropping and the shield returning (probably around 5 seconds), there is a brief window of opportunity for return fire to prevent the recently decloaked ship's shield from coming back online leaving the ship more venerable to incoming fire
5) If there is a delay between the cloak dropping and the shield returning, a stealth rammer cannot deactivate the cloak a fraction of a second before impact to avoid taking a large amount of damage and being venerable to return fire