Wouldn't it be wisest to wear safety glasses at all times?
Consult a labor lawyer. Many of these secret shoppers don't follow proper procedure. There are several laws protecting workers rights. If you were fired on the survey of a secret shopper and it is unjust you can also file suit against the shopper. These shoppers make pocket money for causing people to lose their jobs, these aren't good people and aren't above giving false reports.
If you live in the US, there is an all purpose cleaner called Awsome that is available at most dollar stores and it really is awsome for anything. As far as the toilet, try pouring full strength bleach and letting it sit before you scrub with a toilet brush. DO NOT add anything to the bleach, it will create dangerous chlorine gas. If the bleach doesn't remove it, flush two or three times and use cleanser to remove the rest. Good luck to you, sounds like a lot of work.
That is a tough question to answer with the data given. Something is seriously WRONG! If it was recently installed and still under warranty I'd IMMEDIATELY call the installers and have them repair the unit. A three ton unit is too large for a small and well insulated house. 2 ton maximum for a house like yours. Anything larger is a waste of energy, will short cycle, and will never lower the humidity to a comfortable level. You should NEVER have hot air being discharged into your living area if the system is operating properly. If you mean the house is not comfortable, but the unit is working correctly, then it is because the unit is TOO large.