I would add secret passages that spawn at random spots at the start of each game. You would not be able to ping on them at all and if somebody says something in chat about them the last one traveled through is destroyed. or I would add another epic monster that roams the map and does nothing, unless hit by a champion, then it goes berserk and tries to attack the champion that attacked it.
I'd add a duck to the river. Because we need one.
Increase the overall map size, redo the jungle to make it larger and have more mobs that are wandering in small areas and auto aggro champions that get too close to their "spawn" point. Increase power of turrets, increase number of minions per wave.
I want SR to feel like an epic battlefield P:
Make jungle a bit easier (more meta breaks and freedom), but increase the dragon's strength a little. Also add the jesus buff to anyone in the river because they are walking on water. I would also make a summoner's rift, with 3 bases and three teams hehe the trolling by teaming on one team would be op XD
I would bring back green buff
I would remove the cannon minion from the mid lane. Thats the lane that is easiest to push so why make it easier on the aggressor, especially with the new baron buff.
Also I would love it if turrets did WAY more damage. @ lvl 1, 2 shots and you're dead. @ lvl 9, 3 shots and you're dead. No one respects the turrets anymore. 
Hmm.. I know. I would let every champion have the Awesome Buff of Awesomely Awesome Buffing
I'd add a roaming jungle monster that does the damage of raptors, the tankiness of a scuttle crab, and grants a ton of gold. the monster has a high movespeed, and there is only one on the map that roams through both jungles and sometimes through lanes!. it would be awesome to be laning and see it walk by, then have a fight with your lane opponent(s) for the gold.
Would add more minion types.
One would engage champions killing minions nearby, give it a dagger or a lance. Wouldn't do a lot of damage, but it'd be annoying.
One would support other minions, by giving them little damage boosts against other minions.
I would also make it so if your team has 5 dragons, and then gets baron, your team's Nexus shoots a giant lazer down mid lane, wiping any enemy minions from the lane, and ping the closest objective (be it tower, inhib, nexus) because WIN ALREADY DAMN YOU.
I would make a second summoners rift map, but instead of having 2 bases, there are 3 (or 4). Shaped like an X or an up-side-down Y,with mid lane meeting in the center
not all of the top lanes meet, and not all of the bot lanes meet, the only meeting lane would be mid, giving double creeps, but those minions are only worth half their normal value.
I would bring back mana regen Items, I'm sick of being forced to rush 
so I can use my abilities more than 4 times without running out of mana.
I would add the global URF buff.
I would add a Sphyx for each side of the jungle. (don't ask)
DESTRUCTIBLE WALL TERRAIN (that regenerates over time)
Some champion abilities can break this terrain (mostly ultimate abilities)
also there are now "bomb-wards" in the shop (100g), these wards upon being placed detonate in a small aoe the size of a tower after 5 seconds, and destroy walls. They deal zero damage and can be disabled by ally or enemy by auto attacking them 3 times before detonation.
I would bring back DFG
I'd save that frog. He's probably gotten his soul crushed by the toxic league players. WE NEED TO TELL HIM ITS OKAY TO LIVE!
I'd add a second summoner's rift type map.
I would add bandit minions that attack both sides and are colored black, brown, or dark green, and would have bows and spears. They would spawn out of a hole in the ground that you have to periodically seal up to prevent them from attacking your own minions and towers.
