Yes, it should be replaced if you're doing a major rehab.HVAC should be modern.

Looking for cohost for vacation rental in Jax near the airport. 
Alternatively looking for a OCD cleaning and laundering service. If anyone knows of anyone even someone just starting out please send them my way!

Some of the homes in the area have tried to update and look more modern, painting similar looking (yet not solid/custom oak) wood styles white, adding in more modern looking light fixtures, accent work etc - but it seems 'cheap' looking to me.

Even then you risk losing in court especially given that the lady is older and has likely lived there a while.My advice would be to try and use the current owner's good will, and hopefully good rapport, with the tenants and see if she can work something out with them BEFORE you take possession.

My company is under contract for some land in Westlake to subdivide and build 2 modern new construction homes on.

They are all occupied and the lady that owned it did not have any leases with any of the tenants.

They are the modern time share that nobody wants.

Fans and light fixtures are a quick way to modernize a rental. 

yea, we actually converted our existing garage into a 425sqft ADU for around $50k including labor and materialsand now we're going to build a 650sqft new more modern looking garage/office/storage for ~$150kso all in around $200k invested, but we're adding 625sqft total.  

Secondly, there is this vision for the country which is due to be completed in 2030 which are certain areas in the country that the government wants to heavily develop to be so modern and fancy.