@Shyam Panchal
It all comes to Cash flow .If you are buying this ppty as a rental i would look into is this a killer deal to pass.From the conversation it seems you are buying a top of line ppty which has some minor and some major issues .Any one can say donot pass it on ,it is hard to find pptys as it is a sellers market,that doesnot mean you have to buy a rehabbed ppty (possibly a lipstick on a pig) and then throw money @it again if it is a skinny deal.A NO DEAL IS BETTER THAN A BAD DEAL.
Water heater i would not worry too much will cost 400$+Labor
The AFCI needs attention bcoz in most cities in texas a remodel will not pass city rules if a new breaker box is not installed ,try negotiating with seller on it.Either he puts afci or you get a reduction .It will cost 1000$ + labor
Mold is a concern.How was it fixed ask if they got professional remediation.Ask to see proof.If proper mold treatment was not done and you do like someone said just brush it off with vinegar or stuff you are on the hook if your tenants get mold in their system.Now it is on you to professionally remediate mold for your tenants (expect couple of 1000$) else you are looking @ a lawsuit down the road if the tenant know what they are doing and trust me tenants will
If you have inspection contingency on your contract i would fig out how much the repairs cost and negotiate based on that.