First time posting here.

TLDR: I am a new RE investor and have questions regarding long term wealth generation through RE. My Background: I am 23-year-old recent college graduate looking to purchase my first home/investment property in the greater Denver area. I work at a large engineering firm making around $64,000/year; I’ve saved up for a couple of years now and have around 40k in savings. I am single with no debt and am looking for a 4bdrm property at around the 300k price point ($330,000 max). My credit score is around 750, and I got pre-approved for 330K at 4.5% back in May. I can comfortably save 20k a year (with a 4k fun budget), and I plan to invest all of that into RE or the market.   My Plan: Use a 5% down conventional loan to purchase the property and rent out the other 3 rooms while I live in the 4th. I will live in it for as long as I need to until I can re-qualify for a second mortgage and move into that. Again, renting out the other 3 rooms while converting the first home into a full time rental. My aim is for the other 3 tenants to being paying most of the mortgage down, I do not expect to cash flow, but I’ll hopefully be living close to rent free. I believe I will need to live in the first property for at least a year under the 5% down owner-occupied loan rules, but I am not sure (someone chime in if they know). I will repeat this process until I’ve grown a sizable real estate portfolio (4-5 homes), then I hope to move into investing in larger/higher unit properties.
  My questions/concerns:
1. First, being a complete beginner, I’m sure I’m overlooking and missing things, do any of you see any problems or hang-ups with my plan? What would you do differently if you were in my shoes? Constructive, brutally honest criticism encouraged.
2. I’ve been reading a lot about rolling up closing costs, as well as costs of new furniture into my mortgage. What are the pros and cons to this. I will most likely need to completely furnish this house, I expect that to be around 3-4k. Would I still be able to depreciate those items?
3. From reading about the new tax laws, it looks like RE as become less beneficial from a tax itemizing standpoint, at least for beginners like me. Are there any benefits I am overlooking? The only one I see is that I can now depreciate items with a less than 20-year lifespan by 100%. I plan to use this aggressively to purchase new things, but still at my price point its making it much harder to justify itemizing over taking the standard deduction. Being very generous here are my tax write off #s. I plan to be very aggressive. ($6500 deprecations on ¾ of a 225,000) + ($2200 in property taxes. utilities and repairs) + ($1000 in depreciation of furniture/TV/Appliances) + ($2000 in mortgage interest) ($2500 state and local taxes.) That only equals $14,200, it’s hard to justify taking that over the standard deduction of $12,000 especially because I’ll have to pay back my deprecation eventually (I plan to do 1031 probably, but still ill have to pay it in the future).
4. Any tips for someone in my position? Small hacks that can help my returns? I am big into budgeting/planning/numbers and am trying to track my expected expenses as accurately as possible I’m at a point in my life where I’m willing and excited to expend the extra energy to maximize my potential for long term wealth. This is the best plan I’ve come up with.
Let me know your thoughts! Thanks!