I'll tell you, Plane 5 is much more deadly to me than Plane 4 is. Crawler burrow is the only real threat of death, which is easily negated by getting slash fittings from a warrior. The implosion is NOT so easily avoided even at cap, and is actually the only reason I have died hunting the rift in the last month or two - just walking THROUGH Plane 5 to get out of the rift, is one of the most deadly things I do there. Just ask Methais if you want to know how lethal the implosion there can be!
Not only that, but there are two other issues with hunting Plane 5. First, obviously the XP is terrible and it will take you forever to fry. Second, you will not be able to get bounties there, which will even further hamper your XP gain, and badge progression.
I'm all for under hunting, but Plane 4 is safer than Plane 5, at least if you are prepared.
Honestly, with the way you are planning to hunt/train, Nelemar may be the better choice for you than the rift.
Now, as for perception - I don't think anyone will try to argue that it's some amazingly important skill. But it's a very cheap skill. The cheapest skill in the game! It's so cheap, that it's worth at least going 2x, IMO.
As for perception's effect on stance pushdown - I would not say it's effect is negligible. I would say its effect is completely non-existent! But as for maneuvers, that is a whole different matter!
I actually plan to do some very extensive testing with SMR2, in the coming months, and one of those things will be to measure the impact of skills. But regardless of what that testing might discover, I can still tell you this: Being in full plate is already going to largely impact your ability to dodge maneuvers. Sure, being 2x or 3x perception isn't going to magically make it possible to dodge maneuvers, but every +++ you can throw into it, adds up. Midgar, for example, can only be hit by SMR2 if it's an open roll (Granted, his entire enhancive set is based around maneuver defense
).
Much like DS, or TD, or anything else - the bonus may not be huge, but it adds up. And unlike DS/TD, there are far fewer ways to increase your maneuver defense. Also, who knows what else perception does, that we don't even know about?
In the end, I see where your reasoning is coming from, but I guess I can't agree with dumping perception. Clearly maneuver defense is important to me - I see it as one of those things that is most difficult to overcome, unlike DS/TD which has many ways to overcome. It's also one of the few places a rogue has a leg up defensively, so why not take advantage?
As for full plate armor - I think it's a great thing and a solid plan for any rogue to wear, especially pre and early post-cap. But I'm personally more of an advocate of MBP, since you get most of the benefits of full plate, with far fewer of the negatives.
We don't know exactly what the impact of full plate -AP is on maneuvers, but we do know by something a GM said, that it's equivalent to a little more than 100 PF ranks.
And I wouldn't worry too much about redux. Reaching 45% is pretty easy to do, but if you max out almost every physical skill, you will barely break 50%. I'm talking like 7+ mil XP worth of physical skills, to get a measly 3-5%. I'd worry more about DS, TD, maneuver defense, and your ability to kill more quickly/safely (3x hiding, for example), and the redux will just come naturally while trying to maximize those four things.