1. Does a spirit set on Long-term Binding by paying karma=force still follow me around in the astral within a radius of 100m x magic as normal bound spirits do?
Sustaining a power is a continuos service, so using Endowment to provide me with one of his powers (e.g. Concealment, Natural Weapon, Movement, etc) counts as one service applicable for Long-Term Binding. Using Endowment instead of using the power directly on me, has two huge advantages:
a) I can turn the power on and off at my will and provide for others as I like.
b) My Magic is used to calculate the effect.
2. Is being endowed an active aura, as a spell is and as presumably a common critter power is, so that it will be blocked by astral barriers unless I have Extended Masking?