Converting 2 pipe steam convector connections to hanging unit heater

I have a 2 pipe system, dry pumped return, 2.25 PSI operating max pressure. Almost double boiler capacity for present connected EDR.
One convector location could be of better use if it were repiped to feed a hanging unit heater.
The existing convector is a 58 EDR.
Main in dead man tunnel directly under it is 3 1/2" fed by 4", this is now the first unit connection after boiler.
Horizontal runout is 30" of 11/4".
1" riser of about 30" to 1" angle rad valve.
Return is 1/2" dropping to 3/4" horizontal into 1 1/4" dry return.

I would like to use the 1" angle valve into the bull of a tee, drip & dirt leg the bottom run of the tee and use the top tee run to feed heater. There would be about a 10' riser to the top of the unit heater.
The drip would go into the 1/2" return drop.

For return of unit heater 3/4" drop to tee w/dirt leg & 1/2" trap w/cooling leg?? or not?? then into 1/2" return.

If I read charts right the 1" dripped riser could handle 150 EDR or 36,000 BTUH.
The proposed unit is a Reznor 23/33 rated at 138 EDR or 33,000 BTUH on high speed fan.

Questions: will the piping plan deliver the rated EDR?
Will 1/2" Hoffman 17C angle traps work for both drip and heater trap?
Is cooling leg at unit recommended or not? (there would be ample room 10' off floor)
There is very little room to gracefully add cooling leg for riser drip after angle valve.
Is any air vented needed at unit. (Dry return is open vented at cond pump, but it is 350' of pipe away)?

This is a school with about 12,000 Sq Ft on one floor. Has one T-stat. for building.
Would aquastat for fan only control be best on supply or return?
New unit would be in entry/hallway, not near class rooms.