Just remember, in payware, the customer is your boss. You are getting paid by that person. Treat them with respect, kindness, patience, and they will be future buyers of your products.
Burn a bridge (customer) and you'll regret it. You dont think one person will make a difference, but they are all usually members of forums and that word from one person will spread for ages to others and you dont want that.
If you treat Freeware downloaders like customers, like 'good people' even if they are a bit testy at times, and they stick with you, they will be the many people that buy from you when you transition to payware.
Learning to interact with people professionally is a gift and will really help you. Stick up for your customers and they will stick up for you. Protect them, and they will protect you.
Mind you, there is always a bad apple. Just offer that person a refund with a smile and an apology that you are sorry it didnt work out that time. That person may be back. I have found that some 'rough customers' were actually nice people that just had alot of bad experiences with companies and figured mine was like those. They ended up getting other products of mine.
They are your business in payware. In freeware its a bit different, but payware, they are the boss. Treat them well and they will treat you well.
Now, on a side note. I had one guy write me on the 797 I recently did as freeware. The person wrote me several times, each time with recommendations for rebuilding aspects of the 'freeware' plane, like redoing the entire panel to be flat instead of a slight curve. I thanked her for the excellent advice. But man, rebuilding this, and that and this and that and adding this and that for him, lol.. He doesnt realise how long it takes to make a VC or plane in this media, lol.. Just smile and be kind.
Bill