I appreciate your thoughts and I agree that it's a balanced class.
I agree about it's strengths, and I am playing those - i.e. currently investing in Dodge Mobility, and eventually Spring Attack.
That being said I find your post particularly unhelpful. You have basically said, forget your character concept and shut up and color without addressing any of the points in particular. I understand any deviation from RAW is a house rule and needs to be OKed by the DM... this is why I'm posting in the House Rules forum to work the kinks out of my ideas before proposing them to the DM.
Sticking with your metaphor, I like goldfishes. That's why I chose one. But I would like to point out that there are many varieties of goldfish - some have stripes, others are solid, some have bulging bubble-like eyes, others don't. Variation is a good thing, even among Goldfishes, and I'm just looking for a little help making my goldfish stand out from the school. It was my understanding that variation and tailorability were the hallmarks and strengths of 3.x D&D. I don't think this is impossible or I wouldn't have suggested it. If you do think this is impossible, I would appreciate specific constructive criticism on what you think is impossible about it rather than a dismissal - seemingly without even consideration enough to even read the post (or so I must assume since you don't bother to actually address any of my points specifically).
And perhaps I do need to clarify my concept.
When I say "paladin-like" I don't mean, "a big heavily armed warrior on a horse, who charges in, stands toe-to-toe and bashes away" I mean, "a warrior who stands for good and right and order in the world." In this case he has a different fighting style than the stereotype, but what he stands for is the same.
I don't see an alignment type mindblade enhancement as a problem myself. The mind blade is an outgrowth of the Soulblades own psyche, so enabling a Lawful Good Soulblade to manifest a Axiomatic or Holy mindblade seems to make a lot of sense. There are others which I think that could be added to the list - Merciful for example, or Ghost Touch - but the alignment-affixed ones seem the strongest candidates. When I say I want to open up the list a bit, I don't mean adding any old weapon enhancement I can find that fits, but to add a few select ones that make sense and feed the breed of my desired "goldfish" more than vicious or wounding might. Is this an unreasonable thought?
Is it unreasonable to work on a 3.5 level feat similar to Shield of Thought feat and conceptually, though probably not functionally, similar to the 3.0 Inertial Armor feat? Perhaps requiring the ability to manifest a mindblade and be Kalashtar as prerequisites, taking 5-10 rounds to fully manifest (roughly equivalent to donning a normal suit of armor) and inflicting a skill penalty similar to an armor check penalty due to the concentration involved in keeping it up. Perhaps a basic level, which could then be upgraded further should you want to spend feats to do so which would further increase the armor bonses and penalties both.
As for the "paladin type PrC" I was thinging of basically swapping some things out of the atavist PrC - I like the concept and am really glad that they added a good soulknife PrC I think it was a needed niche, but the flavor's just not quite exactly what I was looking for, so I thought by swapping out abilities UA style I could get it closer to what I wanted.
The Mindblade's appearance of course is purely cosmetic, I just want it to really fit with the character.
He was trapped for three years in an underground R&D facility in the Mournlands and has just been rescued. He has reported to an embassy of Adar and The Path of Light, and reported all his experiences since losing contact. After hearing some of the events he reported to them they assigned him to remain with those who rescued him for the moment in order to gather more information for them on a few topics of interest, renewing his service to them. He is tactically stealthy, but honorable and completely devoted to doing the right thing - so much so that he once refused to join into a fight to help defend the party because he was unsure that they were in the right, so he abstained rather than join a potentially unsavory cause, though when evidence comes to light that shows where the right is, he will not hesitate to join it and fighting against evil. He is merely wary for in his long fight against the Inspired he knows that evil may wear many masks and not all who serve good or evil represent themselves obviously and to be wary of deception - which is after all a key element of tactical strategy( i.e. "All War is based on deception. Hence, when able to attack, we must seem unable; when using our forces, we must seem inactive; when we are near, we must make the enemy believe we are far away; when far away, we must make him believe we are near. Hold out baits to entice the enemy. Feign disorder,
and crush him. If he is secure at all points, be prepared for him. If he is in superior strength, evade him. If your opponent is of choleric temper, seek to irritate him. Pretend to be weak, that he may grow arrogant. If he is taking his ease, give him no rest. If his forces are united, separate them. Attack him where he is unprepared, appear where you are not expected. These military devices, leading to victory, must not be divulged beforehand." as Sun Tzu puts it in “The Art of War” which is why Sun Tzu also comments on how important it is to know your enemy and yourself, "Know your enemy and know yourself; in a hundred battles, you will never be defeated. When you are ignorant of the enemy but know yourself, your chances of winning or losing are equal. If ignorant both of your enemy and of yourself, you are sure to be defeated in every battle," so that you may peirce the deceptions and give yourself tactical advantages. This was written on our Earth, but as the fact that it is as applicable today as it was then, and the fact that it is still taught at military academies worldwide, demonstrates it's universality, it seems that after a war as long and great as the Last War in Eberron at the very least a similar philosophy of battle will probably have occurred independantly there.).
Maybe this will help a bit. And I think my question has changed. I'm no longer asking if such changes could be made in a balanced way, I am confident that they could be. Now I'm looking for advice on accomplishing this task. Thank you all for your help and consideration.