I have seen some buy a decent home only to be told to tear it down as the density laws does not allow for a building to exist on that property even though the building was basically ok, they could not get the needed permits to upgrade the plumbing and electric.

Apart from that, are there any repairs/upgrades that can be done for a minimal upfront cost that will get you a higher rent?

The rents could be increased a bit or upgrade this or that, but to get to 1.5% or 2% gross rent multiplier after improvement is almost impossible.

With upgrades we have planned to the units, that situation will only marginally improve over the next several years.Planned upgrades:New windows - $2500 x 17 = $42,500New HVAC & central air - $3000 x 9 = $27,000Interior upgrades to remaining 9 units - $3000 x 9 = $27,000TOTAL - $96,000This sounds daunting, but over the remaining 4 years of our 5 year plan equates to $24,000/year, or $2,000/mo., which is quite manageable.

One tip for starting out in your are  is while you are starting out and saving money for your investments, start driving / visiting areas you would like to invest in so you get a feel for prices, rents , house conditions etc, and visit and look at lots of homes and open houses so your eye get used to looking at repairs / upgrades that are normal in a particular market.

It had been vandalized, windows broken, etc.

I have actually taken some plays out of that PM's playbook (we are now upgrading out property management software to Appfolio). 

You probably already know that 5+ is considered commercial - that extra unit can cost you thousands more in appraisal and closing costs.  4 units gives you the most flexibility for turnover and improvements (keep 3 units rented while upgrading 1 at a time) and helps to absorb vacancy!  

Such as encouraging newbies to flip a property long distance.I cant think of any thing more risky than someone with no experience with rehab flipping etc.. decides to go at it like presented in that book.. there is going to be a lot of hearts broken and Bigger pockets become smaller pockets.. that's just uber crazy and risky.  

I have a vinyl casement window, where one of the panes of glass has been broken.