I'll post a few images from my most recent playthrough, I think I'll have to start a new one again soon though.
In my playthrough, I generally neglected to max out my DPS in favor of more survivability. If you haven't already, try reforging your accessories to warding. Don't forget to stack as many buffs as you can from potions, and you can also grab a Bast Statue from the underground desert. You can also put down a campfire and a pool of honey for some extra health regen. For Skeletron, I would make a long bridge out of platforms, and then use your fastest boots to run directly away from him. At either end of the bridge, set up some stairs so you can jump over him and then run back the opposite direction. The Cthulhu shield is really helpful here since it lets you change direction on a dime. Once you get the mechanic, you can wire up heart statues to produce a heart every few seconds, which is a great improvement to an arena.
I don't think most of those changes are for the worse.
>moved meteorite to post boss
I agree with this change, because you were able to obtain meteorite armor + the space gun as soon as you found bombs. This allowed you to skip a significant chunk of the early game progression of collecting ore for weapons and armor. By blocking the player from obtaining it early, it forces them to try different gear instead of just rushing meteorites.
>made fishing useless
I'm not quite sure what aspect of fishing is being referred to here. Fishing is highly important on Expert/Master for the variety of alchemy reagents. Endurance potions, wrath potions, ammo reservation potions, etc. are all extremely useful and can only be crafted with fish. On top of that, there are a lot of very useful items, including the demon conch (free teleports to the underworld), a variety of weapons (the crystal serpent, for example, is a very good early-hardmode weapon), and of course the fishing tools (reaver shark, sawtooth shark, etc.).
The reaver shark was nerfed, but like the meteorite gear, this is in favor of encouraging player experimentation. The reaver shark would normally allow you to skip not only the pickaxe upgrades until hardmode, but also allows you to skip straight to hellfire gear. What's the point of having other gear in the game if the player can just ignore all of it and jump straight to the end of pre-hardmode?
I think this was primarily to address its effectiveness against the Destroyer. Prior to the nerf, it was a 30 second boss fight without any buffs (normal mode). Even with the nerf, you can kill the boss in about a minute and a half on Master using the bow.
It was folded in with ranged, which means it also benefits from the same armor and potion buffs that ranged can benefit from. As for the desert, it is now a source of early game ranged armor (the fossil set). You can also get the very helpful Ancient Chisel, which increases your mining speed, and the Bast Statue, which buffs your defense and is a very useful addition to any arena. Plus, the Magic Conch is a free ocean teleport.
>Somehow fucked up summoner even more
The summoner got an overall buff with the addition of whips, but I don't think they were buffed nearly as much as they should have been. They don't have the DPS to compete with magic users, and their overall defense is far worse. If the whips had better crowd control, or if the summoner sets provided more mobility, then I think the summoner would be a bit more viable overall. But as they currently are, they feel far too squishy without enough damage to compensate. Also, one of their best weapons, the Terraprisma, is locked behind a particularly tough boss fight, (Empress of Light during the day). No other class has to go through a similar challenge to get their best weapon, except maybe melee for Zenith.
Checking the patch notes on the wiki, most of the summoning items got buffed slightly, but I haven't tried them out yet.
>grinding rare drops no longer yield as good as it used to overall dps nerfs across the board
>fucked up early game balance overall
I can understand this being controversial, although you'd have to more specific about what items feel like they got undeserved nerfs or inappropriate buffs. I know a lot of items got reworked, like Magic Missile, which can be for better or worse. In some cases, it's important to reduce the effectiveness of a particular weapon so that players feel compelled to experiment with different weapon and equipment sets. If you give the player access to very powerful weapons, then they might not feel like they should explore their other options. To be clear, I don't necessarily agree with a lot of the changes. There have been a number of other changes since 1.4.0, and I have not kept up with what has been buffed/nerfed/reworked.
There's a lot to keep track of here, and I wouldn't be surprised if some of these changes made things worse.
>never actually addressed interesting items being irrelevent quickly
How quickly an item becomes irrelevant is mostly dependent on how fast the player is progressing through the game. I certainly agree that it's disappointing to use a cool weapon, like the Medusa Head, but be unable to find any sort of upgrade for it later on. Most weapons tend to have some upgraded version later down the line, like Magic Missile is eventually replaced by the Rainbow Rod. But for weapons with unique attacks, you don't have the opportunity to upgrade those. It could be interesting to have some sort of system that upgrades specific items by directly increasing their stats. For example, you could take the Medusa Head, but instead of using the Blizzard Staff for its improved area damage, you would "masterwork" the Medusa Head into a weapon with comparable stats. Then you could still use the Medusa Head's unique attack without losing combat effectiveness.
>most items still lack a good upgrade path
This is definitely true. I would very much like it if they implemented some sort of upgrade system for the items that don't have upgraded versions later on.
>master mode is just bulletsponge mode, no real difficulty was added compared to expert's introduction
This is also true. Giving enemies and bosses additional attack patterns would definitely make the experience more interesting overall. As it currently is, you are mostly just taking what you learned in Expert Mode and pushing it to the limit. I can understand why the devs neglected to do add much more to it. Most casual players will never even touch Expert, let alone Master. Many of them might just stay on Journey. This means that they would be adding new content and balancing that content for a relatively small portion of the player base.