Check seller feedback carefully on any BWR purchase outside of Direct
This is to say that, despite the cost that each draw minimally impacts the composition of the rest of the deck, this deck probably has better mana than a 60-card deck with one less color (Im not sure how problematic needing to fetch four colors instead of three will actually be to how games play out)
Put X +1/+1 counters on target creature, where X is the number of lands you control
Historically, the play rate (how much of the metagame share a deck has) of those decks has been low enough that it hasn't been an issue
Ravnica Remastered will be available in Draft and Collector booster
For a beginner navigating professional grading for the first time, working with a UK-based service like Imperium Grading removes unnecessary risk at every stage of the process, from the moment you seal the box to the moment your graded slab arrives back at your door