Since you've got cool season grass mix for a lawn you will want to make sure that that mower cuts no lower than 3". Once a week, twice is better. Bag clippings. Mow in the early afternoon when the dew has evaporated off the leaves. Hey, I had to mow no matter what, rain or shine. Mostly down pours 7 out of 10 days. Sharp blades and hydrostatic mowers were important. Sharp blades...cleaned with alcohol in between customers.
Security issues that Bamboo brought up sounds like a very good thing to be aware of...learn the rules of watering, fertilizing, aerating cool season grass mix lawns. Just cutting the lawn is not the only aspect for a beautiful crop of grass. Edges, fertilizing 4X per year...with season specific fertilizer formulation, watering deeply and not watering until you are able to see your footprints stay down on the lawn is crucial, water during the day, never in the evenings or during the night.
Bagging is very important. I haven't found a real mulching mower with mulching capability ever. Bagging the clippings is easy and those clippings are gold for killing weeds and composting. Allowing them to remain on your lawn is asking for expensive thatching and lawn renewal within 5 years.
I'd hire someone to mow your lawn with a hydrostatic mower, sharp blades, aerate once or twice per year, dump clippings thinly on weeds, fertilize, check pH and readjust when necessary...for the price of a robot mower, you could employ someone that would be able to notice problems before those problems happened. If you hire someone that has multiple customers, insist that their blades are sanitized before they mow your lawn.
Never mow your grass shorter than 3". Golf courses use different seed mixes than most residential lawn crops. Your lawn mix has huge root systems and too short of grass means wimpy photosynthesis that means too little carbohydrates being made to support the roots as well as the top growth. Weak grass is susceptible to disease, insects and weeds. Cool season grasses cut shorter than 3" (3 1/2 inches is best) are very stressed and are unable to compete with weeds...winter.
What is happening with line trimming the edges? The edge is what the eye sees. As long as the body of the lawn is a uniform green and texture, it is the edge of the lawn that creates the professional punch.
And I just have to add this; I've learned that the hours, the WORK maintaining landscapes...it was the mowing and edging that made all worthwhile. To be denied the chore of maintenance and connecting somewhat to your garden is denying you health and joy. Just sayin'. Having to get out and do chores actually gets us out of the house, away from the technology, daily stresses, the clock, to allow sun on our skin, fresh air, huffing and puffing.... and the benefit is clarity of mind, objectivity with emotions and stress and simply feeling a part of something larger. Woo HOO! This is just my perspective, grins.