What sucks is we used to live there for 10 years and paid income tax as a resident, but that is a wash now.

I've been reading quite a bit about corporation vs personal ownership in canada, and i think corporation makes a lot of sense, especially because i plan on expanding eventually to 100+ doors. the corporation just seems like a much better deal for paying as little tax as possible. however, i'm concerned that starting out i won't be able to get any loans, because my corporation will be new with no credit history. i plan on starting with tri/quad/quintuplexes and then working up to larger buildings. does anyone know if it will be difficult to find lenders for these types of buildings as a corporation in canada?

You can't tax a gain that doesn't exist. 

Unlike passive rental income, the income from an active trade or business is subject to self employment tax (a nasty 15% tax commonly referred to a "social security and medicare" by working folks).

I have looked at other areas like Austin and Raleigh, NC and the numbers there are even more crazy plus the I was shocked to see the property taxes in places like Austin, freaking 5K property tax a year on a 230K OKish house.

Remember you don’t have to make quarterly payments related to sale this year if you choose to pay 100% of PY tax as estimated payments.

would you recommend rehabbing over wholesaling or would it be a lot easier to just do judgement liens and property tax as a new investor just to get some capital??? 

You have $1.5+ million home and you're paying $2000 property tax a year, probably a paid off mortgage  if you bought in 1970 for example, and can charge market rate rent (multi units are under rent control with existing tenants, generally speaking, but not SFHs so far) Be really careful with whoever gives you numbers on a spreadsheet whether it's a turnkey company, agent etc. 

If I rehab it now, then sell it, I might get away from capital gain tax as I have never rente the old single house before. 

Because my taxable income was reduced by $18,000 due to my 401k contribution, I saved a total of $5,300 between Federal and State income tax as a result.Therefore, if I hadn't contributed $18,000 to my 401k, I would have paid $5,300 more in taxes, for a net difference of $12,700.