I'd like to help you get an answer on your question but you need to be more specific on what you need to know re pre-foreclosure.
Your best bet is to work with a lender who is approved on doing down payment assistance for first-time homebuyers. Not all lenders are doing these programs. Ask if they are doing the first-time homebuyer down payment assistance programs. There are guidelines to qualify for these programs.
If you are taking out a loan to buy a house, you must have been pre-approved by a lender. All your required documents have already been submitted to the lender and a pre-approval letter has been issued that will reflect the type of loan, purchase price, down payment required from you to purchase a house. Please work with a knowledgeable Realtor in submitting an offer to ensure that you have all the required contract documents and that the terms of the contracts have been explained to you as well. The seller will reject an incomplete offer package. In addition, a copy of your bank statement that should reflect your down payment plus closing cost must also be provided with your offer.
You can go to tenentscreen.com.
Of course you can do that provided you have disclosed this to your lender and to the seller.
You can go to energystar.gov to check.
You can always negotiate that with the seller. However, you need to provide a valid reason for the seller to agree. Since your lender is ready to close on time, you need to also communicate your plan with the lender. Ask your lender when your lock in rate is expiring. Worst case scenario, seller can ask you to pay a per diem which would be the penalty for the extension.
If you can prove that your offer was not presented to the seller, you can report that real estate agent to the Bureau of Real Estate by going to www.dre.ca.gov.
Interior inspection and repairs are the responsibility of the Seller/Buyer. You will need to check with the HOA as to what they cover when it comes to exterior inspection, treatment and repairs.
It all depends if it is an assumable loan. If it is, what is the interest rate? With the current low interest rate, it is much better to just get a new loan. By doing this, you will have a cleaner purchase.