HMS Revenge 1916 & aircraft

While trying to get a better view of a WWI era
British RN BB gun turret, I found:
http://upload.wikimedia.org/wikipedi...le_drawing.png

IMHO a nice set of color line drawings!

OK, not that unusual, both the top (front and rear)
main gun turrets, have wood planking constructed
to enable a bi-plane to take off.
OK, at ship top speed, & bit of a breeze, the plane
could take off, & give scouting capability
(& perhaps if all was worked up very well with
a wireless, maybe even spotting capability,,
although noting, even in 1939&40 that often did
not go all that well,,).

Question #1, under non-combat conditions could
the bi-plane generally land safely on that platform?
(Hey, ISTM, if the battle fleet is engaged & firing,
the least important concern is aircraft recovery,
when out of gas, ditch near a DD & hitch hike home.)

Question #2, when the main guns elevated & fired,
how much of that scaffolding fell off?
Or, was it planned to quickly dismantle & cast
overboard?

Question #3A (while I have someone looking at
this drawing ((??)) I may as well ask a more ignorant
question) Go up the main front mast.
There is here, & routinely, a large 'spar' that
sits horizontal, and atwartship (90 degrees to ship
centerline). I've long believed it to be a optical
rangefinder.
http://en.wikipedia.org/wiki/Coincidence_rangefinder
But I can not find pictures of it at an angle
(or aimed toward a broadside target)
Is it an optical rangefinder, or just a spar?

#3B, if that is not an optical rangefinder, where
is the rangefinder?
#3C, where does the primary gunfire director
crew sit/work?