Talents vs Psionics

[Hanzorigami]

Definitively valuable information Sunrunners and Keeh! Thanks a lot!
I think I understand better now how the stuff in the Psionic Powers supplement works. :) I am glad to see some of my conjectures were right. I'd like to use an example to confirm I got everything right.

I'd like to have True Sight, which is an AntiPsi ability (PP25).
Its cost is 16 points for level 1 and 21 for level 2.
The skill associated is True Sight (Will/Hard).

I need to buy the True Sight ability (requirement) at any of the levels, let's say level 1 for 16 points.

Now, with just that, I could use True Sight as an Advantage and make a success roll against my WILL-6 (I assume the associated Attribute is WILL since the associated skill's Attribute is WILL), and if I succeed, I can use it.

If I'd like to have a bonus, I could either buy some levels of the AntiPsi Talent (5 points/level) to have a bonus or buy the True Sight skill at WILL+x (in order to have an advantage, but I know I could as well buy it at WILL+0 or even WILL-x) paying the cost as a standard Hard skill. I could as well acquire both, the AntiPsi Talent level(s) and Skill at Attribute+x for a better bonus.

Now, I assume that by buying the True Sight ability I could also use Shared Sight (Is this correct?). My thought is that since Shared Sight has no skill associated (just a default) and no cost it is an ability that requires (depends on) having True Sight in order to be used, and that its "cost" is the cost paid to get the True Sight ability.
In this case, how should I proceed if I want to use Shared Sight?
The default is True Sight-5; cannot exceed True Sight.
I know the first True Sight mentioned is the True Sight skill level with a penalization of -5, but what does it mean "cannot exceed True Sight"?
Somehow I think this second True Sight is not the skill, but the actual ability, but yet I do not quite understand how could True Sight-5 exceed True Sight.

I understand that if I have the True Sight ability and the True Sight skill, I could use Shared Sight with a success roll at True Sight-5 (I would yet have to figure out if I am not exceeding True Sight, which so far I do not quite understand), but what if I do not have the True Sight skill? Could I use Shared Sight with a success roll at WILL-6 just like with the True Sight ability?