Would you advice to go with dark wood or with lighter one?

Also a couple of the burners won't light without holding a lighter to the gas.

There is no one size fits all.Very well known investors go lighter on the leverage, and some go all in.In between 50-75% is the ballpark

The mantel is also a rough wood that I suppose I could paint but once that is done, it's done and if it doesn't turn out good then....Some ideas after looking at what others did were to have stone put over the brick to give it a lighter color and more updated look.

BTW, how do you paste another poster's comment (like I did yours above) and have it be a lighter shade like I see on the forum all the time. 

You have to have a lighter touch with the property management.From a legal perspective in SFRs, yes, I always give 24 hours notice before I asset my right to access the property, WITH TWO EXCEPTIONS, an emergency situation constituting a danger to my property, the tenants, or the public at large, and shoveling any public sidewalks running through the property.

Paint the exterior stair case and window frames a lighter colour if you must and something contrasting on the shutters and doors. 

A couple small areas on the front that were painted with a lighter color (almost the same though).

Or, I thought about just throwing up some lighter shutters & painting the stucco a light color. 

Cheap budget upgrades for your 10K budget, I would definitely:Paint the whole house repose grey (Sherwin Williams) with white trimIf flooring isn't the same or needs to be replaced.. a nice, lighter colored laminate throughoutNew baseboard trim, 5.25"H adds a nice touch (and paint all trim bright white)Kitchen.. if old cabinets, paint them.