Yeah, paddles offer about the lowest concealment level possible. They project quite far from the body, don't have any "smoothing" function to reduce the bumpy projection away from your hip. They are convenient, at the expense of almost all concealability.
3:00 is going to be your least concealable position -- right out there at the point of your hip bone. Even 4:00 may not be far enough back to really hit the sweet spot. Don't go any farther than the 5:00 position or you'll start putting it over your kidney or even spine -- not good -- but 4:00 - 4:30 is about where most folks find their concealment sweet spot.
Nighthawk/Wilson Combat style slight forward cant.
Doesn't help much. Wilson does offer a pancake style holster, though, that would likely suit you much better.
No way this will hide under a T-shirt.
A t-shirt?
Yeah, not much conceals really well under just a t-shirt. If you're going to conceal with only a t-shirt you might end up needing something like a tuckable IWB holster to really make that satisfactory.
How picky is IDPA if under a light vest.
IDPA? IDPA just requires that the holster not be directly visible when you hold your arms straight out to the side. The rules say nothing at all about "printing."
Did buy an Askins Avenger, have not tried it.
That's the same basic idea as the "Bruce Nelson" or "tunnel" style I posted before. It will give better concealment than any paddle holster, but not as good as a pancake/speed-scabbard style, and definitely not as good as an IWB.
But, as others said, worrying about printing is sort of a newbie mistake. No one's looking, no one notices, and you will stop feeling conspicuous in a few weeks of carrying experience.
Not for action-type sports, the cross draw might conceal a little better on some one with a front tire.
Well, you're right that cross-draws aren't applicable for competition as they pose grave risks to bystanders from the muzzle being pointed the wrong way when you clear leather. But they don't really offer the concealment benefits some folks think they would. They just redirect the lump from there to here. The holster features that would tuck a gun butt well in against your gut on the weak side will tuck it in well against your hip on the strong side, too.