No, not really, but in some instances he might be slightly holding back in power. There's also something Shirou hasn't realised yet to fully utilise his Tracing, but that will be a development for him, something he will overcome in the future. I know Archer was able create a reality marble twice with only his own mana, also blocking gae bolg and surviving an attack from Gilgamesh, but Archer was more experienced. Now Shirou was only able to use the reality marble because of the crest given to him by Tohsaka Rin. Your choice really, but if you all want to know what I think for Shirou:Ĥ. To be honest, I don't find this crucial information and I probably won't even mention it in the story. To explain everything simply: THE STORYLINE AND EVENTS WILL BE THE SAME AS IN THE GAME, BUT THE TRAILBLAZER IS REPLACED WITH SHIROU EMIYA. And Elliot did take Shirou into account.
I won't reveal if he has a good relationship with the Stellaron Hunters before he lost his memory because the game's storyline is still ongoing. He has a suspicion he's forgetting a few things because naturally when he was sucked into the hole of the grail with Gilgamesh's dead body, shouldn't it have been with him as well? Thats how he appeared in Herta's station with clothes he's never seen before. But he just doesn't remember as a side effect of the Stellaron being sealed inside of him. Shirou has the Stellaron and he knows the Stellaron hunters. However he never had feelings for Saber or Tohsaka Rin.
He is from the Unlimited Blade Works route, however I mixed it in a little with Fate/Stay Night to where Illyasviel wasn't killed by Gilgamesh. This chapter is going to explain a couple of things: