I did miss the number crunching
...
Are there more options at higher levels to reach the same sort of character tweaking that exists in 3.5?
I'm going to go out on a limb and say that these statements/questions are a good indication that 5e isn't really what you're going to want right now.
Eliminating most of that stuff is considered a feature of 5e, not a bug. There is nothing like the level of ongoing customization you can find in the library of 3.5e or Pathfinder books.
You might be right. While several of our players would often find themselves at 1 or 2 hit points during any combat encounter, none of them were ever at 0 hit points. So often my barbarian would come in the next round, and cut down what ever enemy was attacking them. One short rest later, and we'd all be healed up. Maybe the system is intended to be this way. It feels deadlier, but you're able to recover much faster from injuries.
At 1st level the game is potentially deadly. That initial goblin fight can end up as anything between a speed bump and a TPK depending on the players, the character, and the dice. I love it.
After 1st level, the game very quickly gets a lot easier for the players. A lot. They have enough cool powers and resources to handle the assumed adventuring day without much trouble most of the time, and challenging them at high level tends to call for hordes of minions supporting the stronger opponents, or setting cheese, "Um...so,
five more black dragons come around the corner!" DMs must get in the habit of throwing in plenty of minions. Except at 1st level, you should almost always annihilate a solo opponent unless they are several levels higher than the party. Using the full adventuring day as suggested (not requires, just suggested) makes it go more smoothly.
The strength of 5th edition is that its immensely flexible and not reliant on the system to make a game for you, but reliant on the GM.
In our last game our 1st level party was being stalked by a displacer beast (the dice hath spoken!) I made sure the characters with the right knowledge skills and checks were well aware that this was a deadly opponent. The first time it attacked, the fighter chose to scrape up some dirt and throw it at the creature's eyes rather than the more standard readying of an attack for when it came into range. Even though the monster was 20' away, I ruled he was strong enough and there were enough pebbles in the dirt for it to work. I called for an attack roll, it hit, and therefore the displacer beast "de-displaced". This was the awesome of 5e flexibility at work. There is no way you could do that in 3.5e without laughing at the rules.
(As an aside, the temporarily partially blinded creature retreated, and then attacked the party later with surprise (but a horrible initiative roll, due to it still being under the
hex the warlock tossed on it earlier). Most of the party used their Inspiration to attack it, and they actually managed to drive it away without anyone getting hurt--though I may have forgotten to give it one of its attacks, which could easily have dropped anyone.)
Yeah I really do think Tony is right, a proper DM can make any system great.
I would say, rather, that a good GM can make playing with just about any system fun, but a well-matched system will improve any game.