"There is no need to clean, fix handy-man repairs, paint or stage since buyers can see past it and will do their own thing anyway." Nothing could be further from the truth. Buyers want properties in move-in condition as well as the lifestyle associated with a new property. Not giving/showing it to them will cost you tens-to-hundreds of thousands of dollars.
"I've watched real estate TV shows and negotiate all day at my job so I can sell/buy my own home without a broker". Each industry has its way of doing business. Most homeowners buy/sell 3-5 properties in their lifetime. Top real estate agents do hundreds a year. Their experience will get you more money/value than their commission.
"I will only my property at a time that is convenient to me. After all, if they really want to see it, they will come back." About 50% of buyer will not come back if they cannot see it when they wanted to. Their attitude is: There are other properties out there and this seller is not real if they cannot show at the time requested