In-flight comet mining for water and fuel

Dear All,

I would like some advice and comments please on the feasibility to
mine comets in-flight on a hypothetical futuristic spaceflight mission
towards Alpha Centauri, I have outlined in this research article:-

http://uk.geocities.com/aa_spaceagen...ropulsion.html

Specific questions I have a

Is it feasible to have a large scale robotic arm on the scale of some
2 or 3 kilometres in length that can stand the stress of gripping onto
comets whilst the ship is docking with them (gently) in-flight?

Based on the current material science advances, is this kind of
framework conceivably viable for tens of *thousands* of years on such
a long voyage well into the future? Will it be structurally robust
enough to withstand several docking maneouvres with comets?

Since the main asteroid ship is rotating, if the comets are of say
just a quarter or so the size/mass of the actual starship (the
asteroid), when gripping comets in-flight, will the spin rate of the
ship slow down too dramatically, when such a comet is gripped by the
robotic arm?

What is the best method of *steering* the starship (without affecting
its spin) so as to "pitch" it from side to side or to turn it around?
My own view would be to apply 'pulse' thrust at favourable points
during the rotation. Is it feasible to do this?

Really appreciate any thoughts on these.
Many thanks.
Abdul Ahad

MODERATOR: Please can you consider this one in a serious light. I am
getting heavy criticism on this aspect of my research article. Please
be *kind* and let my post through... (I promise I wont pester this
group again!). Cheers. Abdul.