I'm allergic to bees and one of my neighbors has several hives.

For example, hostile dogs (insurance cost), significant impact of existing tenants (the attached unit has someone allergic to dogs, etc.), etc.Note the HUD direction is far more lenient on their definition of a support animal than the ADA definition of a service animal. 

I am allergic to rude people that know it all so I just try to be nice.

You don’t need college for the last two.Some people are cut out for classroom learning and some are almost allergic to it.  

But since we "use" the home when it's not being rented we say "sorry it's our home that we rent occasionally and we're deathly allergic to dogs" As I'm typing this there's a banner on the right telling me to register my emotional support animal.

I'm allergic to cats, so that is an automatic no go from me.

If one of the other tenants was allergic to dogs or they had a fear of dogs, then you could say the request is unreasonable and deny them.

thanks @Tim Herndon indeed I'm on chrome i'll try Firefox, i'm on a machine that might develop an allergic reaction to Internet Explorer. 

Apparently R30 is required but the city had mercy on my soul as I'm also having an allergic reaction to the dust in the house and they know I'm living here.So.. insulation inspection is set for tomorrow at 8AM and the drywallers will be here waiting for the go ahead.

The problem with holding him responsible for the cost of the air test if nothing is found is that there is no clear pass or fail for the test, so he could say "well there is a slighlty elevated level of this type of mold which normal people aren't allergic to, so you have to pay because I was right...