1. Can I use the De Minimis Safe Harbor for all of the expenses of this project because none of them exceed $2,500 even though the cost of the total project is over that?
Yes, because the safe harbor is $2,500 or less per invoice or item.
See https://www.irs.gov/businesses/small-businesses-self-employed/tangible-property-final-regulations#Ad...
2. Am I required to use the De Minimis Safe Harbor for these expenses because it is an all or nothing election, or can I choose to capitalize this as one project?
You are not required to use the safe harbor in the first instance but if you do, then you must use it for all invoices/items with a cost of $2,500 or less.
