Tax planning for subdividing and building a new house for sale

[Andrew S Austell]

After buying a property in 2015 i subdivided the lot.  I've kept the original original house and lot as a long term rental. In July 2019 I started new construction of a single family home on the subdivided lot. Construction was finished and new house and property sold in 2020. Proceeds from sale are being held by a designated 1031 intermediary and if I find a worthy property in time I'd like to reinvest those proceeds. 

Now my questions:

1) Sec 1031 like kind exchange only defers capital gain taxes, so am I correct that any gain (about $150k) from the construction of the house will not be deferred and in fact will be subject to regular income tax rates?

2) Can I treat the land as separate from the building when determining income? The land when I purchased it was worth about $50000,  the site value at the time of sale was roughly $95000.  I'd like to think that $45000 in gain can count count as long term capital gain and be subject to the more favorable rate.  Also would be nice if that $45000 could be utilized for the 1031 exchange deferment. 

3) Finally can I confirm my expenses that I incurred in the construction process (plans, permits, materials, labor) will all land as expenses again the income made in the sale on my 2020 taxes even though a large chunk of those cost were incurred in 2019 during the construction process?

Thanks.