When did buyer's agents start training on  buying "off market" without agents, subject to, wraps, seller financing, lease options, land contracts, fix & flips, rentals, taxes, asset protection, etc, etc, etc.

Eventually I will invest in cash flowing properties out of state.I'm looking for tips and advice on being a land lord such as maintenance, rent collection, taxes/accounting, legal, and things you wish you would/wouldn't have done starting out.

As a sales professional, you'll find that one of the greatest benefits of investing in real estate is tax saving -- I'm not a CPA and can't advise on this, but I've personally saved a fortune through REP status and cost segregation. 

Also if someone pays taxs through Captiol Gains would one have to pay income tax on said amount of profits?

If your doing anything close to this tye property better be a 100% home run .Otherwise, we didn't do a portfolio loan until we had 5 houses and supporting tax returns and did everything cash up until then. i wouldn't do it until you have some track record before jumping into leverage and a heloc is made to use and pay off quickly.

And what are the future ramifications when withdrawing from the 401k since part of it should not be taxed?

Navy Federal, as an example, needs a long time to close and requires tax returns, but has a 20 year draw and a 20 year payback period…takes much longer than others, but that payback period is amazing.  

Make sure the money you receive from rentals pays for all of your out-of-pocket costs, such as upkeep, insurance, taxes, and mortgage payments.Underestimating the Outlay: Add up all of the costs that come with owning and operating rental properties, such as capital expenditures, repairs, vacancies, and property management fees.

All commercial loans will now have new covenants if borrowers do not provide timely personal financial statements, personal tax returns, business tax returns, rent rolls (if applicable) timely.Personal financial statements and rent rolls (if applicable) are due within 60 days of the expiration date of the personal financial statement.

LLC has more tax treatment options (taxed as a sub S) and better protection than a land trust, if managed correctly.