This has puzzled me quite a bit. 

That's puzzle piece number 1.Puzzle piece number 2 in the 1031 exchange is your reinvestment requirements - in this case you sold for 500K so you must buy for 500K.Puzzle piece #3 is that you netted after mortgage pay off 100K in cash - So you must use all 100K in the next purchase or purchases.So now just run the scenarios - your potential tax bill in CA on 100K of profit could easily be  30,000 or more.If you do a 1031 and buy for 500K and use all 100K in cash then you would pay no tax.If you do a 1031 and buy for 400K then the IRS perceives that as taking 100K in profit called boot (yes you might say that it is a return of capital or whatever but they have nuclear weapons and you don't so their interpretation wins).  

Percentage of ARV is only one piece of the puzzle. 80% of ARV with $1k repairs is a completely different deal than 80% of ARV with $40k repairs. 

Share RE statistics in the area, have a crossword puzzle or something fun. 

They are all important skills and pieces of the puzzle. 

Also, great plan to get a job soon - income is a big piece of the puzzle that many gloss over.

The other piece of the puzzle is finding the properties you wish to purchase with the 1031 funds.

The deal is the other piece of the puzzle here. 

Pursuing my degree is a piece of the puzzle for me.

If you're missing the financial side of the puzzle it's probably not a good idea to begin with.