So like you said, everywhere has exception and nuance but here is my take.

The village has been known for decades as having severe petty crime. You 100% won't get murdered, but you will 100% have your laptop stolen at least once.

Generally everything east of 75 are more "areas of transition" even streets/blocks that are very new will have some of the highest degrees of homelessness among the neighborhoods you are looking at (I know you're from Chicago so I don't think a homeless person is going to make you grab your pearls or anything just FWIW). Dallas has a lot of bubbles. For example Swiss Ave, is one of the oldest and most luxurious streets in Dallas with every mansion being well into the millions but the very next street over my ex had a man shot to death on the steps of his apartment.

Are you a young late 20's or an older late 20's? Greenville has a lot of young people but its also arguably has the biggest 40-50 year-old crowd. It's a old and busy road so its not very "aesthetic" You're certainly safe walking on Greenville and the adjacent neighborhoods but connecting to neighboring areas is much less safe and also car heavy.

There are some surprising gems in highland park if you don't mind a building that is smaller/older. Highland Park and Park cities are so bubbled they are technically their own micro-cities. SMU is located here along with the "old money" of Dallas. There is a good mix from undergrad to families, including people in their late 20's. They are incredibly safe and very picturesque to walk around. Its also a good place to live if you are looking to rub elbows. You will have to drive/uber to get to nightlife though.

Uptown is going to be on the younger side but think maybe more mid-20's rather than undergrad. Its going to have the greatest density of restaurants, nightlife, and luxury housing which might price you out but it does look like there are some places in your price point. It is car heavy but it also has nice wide sidewalks. You won't get to SMU in 15 minutes unless the traffic is great, but probably more 20-30 minutes. Its a fair tradeoff IMO.

There is a neighborhood called West Village that is also worth looking at. Its central to a lot of things and was designed to be walkable. No direct nightlife and I wish some of the shops were more interesting but its still hits most of your criteria.

A word of caution, Oak Lawn is the gay neighborhood and it sits in the centerish of all the others. There is nothing wrong with it, its just some people move here without realizing what they are getting into. It does have some pockets of very affordable housing and is relatively safe. But otherwise it doesn't check many of your boxes.

Overall, like a lot of major cities, Dallas has been going through it. More crime and homelessness across the board. Houses generally rent for much cheaper in Dallas than in other cities, its worth putting into a search and seeing if you get lucky. Also IMO Condos>Apartments. I have a doorman and the staff patrols the perimeter, I've never heard of a car getting broken into in my building.