I am assuming I will have to remove part of the ceiling above the kitchen to access the drain lines to the bathtub and bathroom sink.Do I need to acquire permits for this job and what would be the best way to go about replacing the whole cast iron pipe from the roof down to the crawl space.

I have seen beautiful houses reduced to wrecks in only a few years with folks tearing out the inside wood to burn in the wood stove, cutting a hole in the bathroom wall so the horse could drink out of the bathtub, (in fairness he was drunk when he did it), piles of empty booze bottles almost as high as the junk cars. 

Kitchen, bathroom (excluding bathtub), carpet & popcorn ceiling all had to go.

Kitchen, bathroom (excluding bathtub), carpet & popcorn ceiling all had to go.

absolutely but don't feel bad, even with the older ones there will ALWAYS be a few undetectable $$$ surprises.We had a horrible chipped, colored many times, bathtub & leak prone tiled surround in a circa 1978 SFR & we didn't have the time to rehab it.

Most have no idea how to be responsible renters and see no harm in never cleaning bathtubs  or putting up murals and hanging bikes from ceilings.

The bathtub can also be refinished for a reasonable cost. 

If the prior tenants did a great job cleaning and missed a few spots I'll send a specific list of items that need to be cleaned (vaccuum, wipe down countertops, tenant missed some items on the bathtub). 

Daniel, I would check out to see if there are any bathtub refinishers in your area.

Polish up sinks and bathtubs to a. high gloss with automotive polish before you show a house.