That’s kind of redundant with cryo shield, which already exists to block melee attacks.
I don't think redundancy would be an issue as there are multiple ways to block melee attacks (Parry, Spear Guard, Guard). It would be in a different psi school too. Although now that you mentioned it, perhaps cryo shield could receive a buff that enables the shield feats. Have Shield Bash sacrifice a shard on use and maybe even deal extra cold damage with a chill debuff. As it is now it's pretty poop imo.
From the way you describe it, it just sounds like giving riot shields to all kinds of armor instead of just riot, which would make riot armor pointless.
True. Part of the reason I suggested (OP reposted) this was because I was bummed that the shield feats are restricted to Riot Gear. Having a melee shield on top of good armour would be huge for sure, perhaps the +10% penalty could be increased to 25 (Tungsten shield is 26) to compensate. When you add up all the reqs to get the most out of the proposed PK shield (feats, melee stat investment, weapon restrictions, a psi slot, psi points, armour penalty, 8 str req for Shield Arm) it would be quite costly like Riot Gear is. I don't know if Cognitive Interruption cancels Force Emission, if so that would be another thing to consider.
Also, why would you need 5 str if it’s a weightless psionic projection?
I thought that would be better for gameplay balance. Perhaps instead of a str req it could benefit from Corporeal Projection somehow (more damage blocked, or +1% block chance with each point of str above 5).