Disclosures, Agents, Offers, First Time Buyers, & Inspections

[Dale Porter]

We are first time buyers. We put in an offer on house after our agent showed us disclosures and didn't highlight any areas of concern. We attended the inspection and our agent didn't . Inspector told us HVAC needed replacing due to age, but it's working fine. We asked for compensation or replacement from the seller, seller refused - which makes sense. 

We later realized that the age was disclosed up front and that inspectors often highlight HVAC age on the report.  Is this common knowledge to real estate agents? Then we could have asked for closing costs paid by the seller, lower price, or something else up front to ease our worried minds.

After talking to other folks we realized that we had asked for "unreasonable" repairs. 

Now we are in a pickle and feel like it's not fair to the sellers if we back out for this reason. So, is this something that we should have been educated about by our agent at the time of putting in an offer? Is it our fault for not researching the average lifespan of these systems? Are we bad buyers if we back out?