I just looked at your level in detail. There are some MAJOR flaws in design:
1. I don't like the Thing-based scenery at all. Get rid of all the THZ flowers. Why would there be flowers--even mechanical ones--inside a building? And you should also eliminate the flame jets.
2. The level is STILL incredibly flat and plain. Vary up the textures, and add some machines and stuff to jump on and hide behind, as well as more and larger upper levels. Additionally, your recent attempt to vary up the textures was not good. It makes no sense to combine textures from GFZ, HPZ, and ERZ. Also, don't make the level that square...add some protruding sections to make the rooms more interesting. Here's a tip: Only about 10% of scenery should be Things. The other 90% should be creatively arranged sectors. I recommend you open up the official levels in SRB2 Doom Builder and take a look at how complex their design is.
3. Don't use Random Monitors...they don't weight the powerup frequency, so players who break the monitors will get a disproportionately high amount of strong and/or disruptive powerups. Use Strong Random Monitors and Weak Random Monitors instead.
4. You need way more rings, and you need to spread around the rings you have much better. It's not only ugly to have square clumps of 50 rings in random parts of your level, it's also bad for gameplay. Rings should be spaced so that no matter where a player goes in your map, they can obtain them at a reasonable rate. I recommend that you replace all the rings you have right now with lots of scattered sections of rings throughout the level (I recommend that you use lines of 5 rings and circles of 8 rings). Also, separate the rings by at least TWO grid spaces, not 1. Not only is this more aesthetically pleasing, but it also means that players will sometimes miss rings they're trying to run at, leaving a couple behind for stragglers to collect.
5. You need to have WAY more than seven Chaos Emerald Spawn Points...if you have only seven, the emeralds will keep showing up in exactly the same places. It's much better to have fifteen, twenty, or even thirty spawn points, so that the emeralds end up in random parts of the level and players have a harder time predicting where they will turn up.
6. You have no Match Starts! That means that everyone will always spawn at the Player 1 Start. Put a bunch of Match Starts all over the level, so that people will spawn in random places. Also, you don't have a Tag IT Start, either.
7. The weapon placement is beyond horrible. You have a section with two Rail Ring Panels within thokking distance of each other (and also really close to two random monitors, which, as I previously stated, shouldn't be there at all.) You have another place with Rail, Scatter, and Explosion Panels, each one placed literally 32 fracunits away from their respective ammo refills. You've got another Explosion Ring Panel on the other side of the level, also right next to a pair of Random Monitors. There are no Automatic Rings or Bounce Rings anywhere to be found.
But the very worst sin you have committed is
PLACING 3 GRENADE RING PANELS TOGETHER! Why the heck did you do that? Did you do that because you noticed that Grenade Panels only give you 5 shots, and you wanted all the weapon pickups to equalize the ammo? That's a TERRIBLE idea. Whoever gets to the Grenade Rings first will OWN the fight, period.
I think you really need to look at this SRB2 Wiki article. It'll REALLY help you straighten out that mess:
http://wiki.srb2.org/wiki/Level_Design_101:_Match_and_Capture_the_Flag#Weapons
8. Secret areas in Match levels shouldn't be as hard to find as secret areas in Single Player. I mean, yeah, they should be a little tricky to locate, but if they are as ridiculously concealed as they are in your map, hardly anyone will go in there.
9. You have horribly overused springs in this level. For heaven's sake, don't make springs the sole means of reaching high places...be creative. Add moving platforms, create staircases, make fan sectors...just vary it up. The spring sections are ugly and repetitive.
Oh, also, why did you choose to make the level MAP91? The first default Match slot is MAP90. Just saying.