With the intent of doing most of the reno myself at least for the first properties as i have a little bit carpentry and plumbing background  I currently do not have any investment properties.

Even if it's not in floodzone , your investment can get flooded by rain, sewer or plumbing problems. 

I found amazing plumbing, Eletric, drywall and HVAC guys in Pittsburgh and I would recommend them to anyone!

Questions to local builders and contractors: what are the average costs to add a small kitchen (8 x 7 ) in a the living room (plumbing work, electrical and cabinets) and also half bath ( 6 x 6) in San Diego. are any legality issues or costs that need to be considered?

I'm going to file for a permit ASAP, was curious if Easy Permit application works for rerouting plumbing and electric or if I would have to go through a different process.

In one of our fourplexes, we a tenant (or tenants) who are flushing wipes, paper towels, and other unknown objects down the toilet which is causing plumbing issues.

I assume if major Cap Ex items, plumbing, electrical, roof are new or newer Cap Ex and maintenance will be less.I operate my rentals with assumptions on vacancy, Cap Ex and Maintenance.

This vacancy happened in 2017 and was the result of a tragic sudden need to end a lease due to domestic violence. 

@Jenny Sung I would be able to run you some ARV comps today, if you wanted, but it sounds like you are already comfortable there.Roof and HVAC are your big items here - the minor plumbing items can be fixed in a day or two. 

The escrow company does the bulk of the work after that.If you are using a bank for financing they will require the things that protect their interest.If you are using cash don't forget to order homeowner's insurance.If you are new to investing you want to have an inspection done that should cover at least the roof, HVAC, electrical, plumbing, drainage & foundation because those are expensive to fix and you need to know what expenses you are facing in the future.