*unplayable*?- depends on what your doing. Difficult? Yes, and you'll probable need breaks. It also depends on whether or not you can spend money on the uniques that can be slotted into health for end, namely: miracle, numinas, pancrea. End proc in stam from P'shifter. How many end slots you can afford to put in attacks, toggles, etc. Will purple sets be used? Some have end bonuses This is the simple answer.
The complex answer will be something like: evaluating the end consumption on your toggles and your attack chain in EPS and compare that number to your recovery to get a sense of end loss and determine a rate of "decay" for end. Some people have a better "sense" than others (which seems to be related to math skills 
, dont look to me I just understand the principle. When it comes to practice my numbers are consitantly off).
Miss Arc #147491: Rise of Bedlam
AKA Iron Smoke @Champion Server
Other primaries get along without DC and don't take CP. My DM/SD doesn't have either at level 43 and my end usage is only an issue in drawn out fights. So it will depend on your slotting choices and available funds.
Poisonous Ice 50 Ice/Rad
Icy Jax 50 Ice/SS
Jaxon Penn 50 Shield/Mace
Cpt Clax 50 Thugs/Dark
Lady BlackIce 50 Dark/Cold
Lady Black Ice 50 Dark/Ice
Bella Jax 50 Storm/Sonic
Operative Jax 50 SoA
Level 50 Trick Arrow Alts
TA/A-Plant/TA-Bots/TA
Level 50 Claws Scrappers
SR-Regen-DA-Invul-WP-FA
I'm trying to build a DM/SR that is softcapped but does not have Dark Consumption nor Conserve Power.
Is this going to be an unplayable character considering the end drain and only have Stamina as a recovery tool?