Im more afraid of changes and additions actually, Tsukihime is way more atmospheric than Fate and if Nasu starts inserting that Extraverse & FGO era in-your-face obnoxious humor into the script he might break that atmosphere. The stories Nasu has been telling most of this decade are also way more bombastic than what Tsukihime has any need to be, so theres also some scepticism on my part if modern nasu is compatible with old nasu. I dont mind changes or additional story at all, on the contrary I welcome fresh tsuki content with open arms, but i just hope whatever changes he makes still feel like Tsukihime.
Also some of my all time favorite TM music pieces are the Tsuki title track and the Tsuki eroscene track, and while the iconic af title track is obviously safe im worried about the eroscene track will be completely scrapped since the remake wont have eroscenes.
Those backgrounds are real photos they just manipulated to look less obviously real. They were making the game from home with the budget of Takeuchis sold Eva DVDs. The main selling point of the remake is updating of the presentation to a modern commercial product standards, so you will definitely be getting your wish.