Unless you have a very beautiful garage door I would paint it a color that blends with the brick IMO they are all too much in your face as is I loved it when the garage was at the back of the house not front and center

There are discrepancies between the two plans you have provided, so it is difficult to understand what has been built and what is proposed. That being said, the powder room will have more of an impact on the garage space than you are indicating, and think that will have negative impacts on the garage which you will want to avoid. The location by the dining room and stairs will also require significant changes to the plan in that area (powder room is still represented too small). The powder room adjacent to the pantry seems like a great place to put it, or in the ancillary seating space to the right of the main living seating. That seating area does not seem to have a great functional importance except to have the dining/living/side living space extend across the whole house, unless there is something happening that isn't apparent from the plan view alone.

Arun, Hettich, Hafelle do have good sliding hardware available. The specifications depend on the size of the ward rone shutters. Topline 22 is a tried and tested product. There is no ideal comparison of custom vs readymade as there are way too many variables. Thanks, Nitin Cornerstone Designs, Bangalore.

Also it is not necessary to go for uPVC. I am preferring uPVC because it looks good. Any other good looking options are also welcome