I play bots regularly. I've lost about 10 in my career and have about 2300+ wins. I've seen it all and have even done some of it too. Like if an ally is teleporting I will pillar them to interrupt their teleport. But I only do that if I am 100% confident in my team.
As far as how to deal with arrogance and poor manners, I am usually better at playing the game than the majority of those player.s If you show them up half a dozen times they tend to leave you alone. If they still talk smack I just point out the stats for that game and go about my business. If they are better than me I just give them a gj or two hoping they shut up. Otherwise I just ignore them.
Toxicity I try to put the bullseye on my back in hopes that they leave my teammates alone. You can do this easily by mildly taunting the toxic player or by downplaying their decisions. I've been told that I am "no fun" to troll and know how to waste a troll's time. If Tahm eats you just press b. He cannot eat an ally who is backing. If Trundle is pillaring you while you are backing just sit still and bad as soon as he initiates a pillar. By the time it comes off cool down you will be back at base. Same with anivia walls. Kalista ults you can actually use to direct when and where you go. Launch yourself behind them and leave them for dead. Bard ults are too infrequent to have a legitimate strategy to combat it.
When they build troll build I will ask why they are building that. I treat them like an afk/feeder until they prove otherwise. I suggest an item to them. They usually ignore me but I try. Sometimes you can suggest some troll items for them that at least have a useful active on it. Like randuins omen on Quinn or frost queen on Tryndamere. Sometimes that works if you word it like so "Quinn please don't tell me you are planning on building a randuin's omen." They usually try to rush it to spite me but in reality its doing what I want them to do.
Kill stealers don't bother me because I simply don't care but if they bother you just ignore killing the enemy for a little while. Free farm. Don't even bother harassing the enemy. Waste the other guys time. Don't bother with buffs as he will just try to snipe it. If you do try to take one take it when an ally is going for a kill or dragon. Make the kill stealer have to choose between taking your buff or an ally's kill. These players are only annoying early on as the kill gold values decrease the more they get killed without getting a kill. Sometimes I will make small talk with them, let them know they really don't bother me. Sometimes I make it into a friendly competition and we take turns kill stealing one another and recognize when he beats me out. Personally these are the easiest toxic behavior to manage as they don't do anything to make you lose the game, just to steal the spotlight from you a few times. Not the end of the world. Don't let this bother you.
