Lag is a serious problem, and it sounds like most of your problems stem from lag. There are a number of different kinds of lag: graphical lag, server distance latency, and ISP-related lag.
Graphical lag is when your screen gets herky-jerky when lots of monsters and projectiles are on screen, and can be remedied by getting a more powerful system or cleaning up your existing system.
Server distance latency usually presents itself as a yellow or red bar, and events happen ~200-500 milliseconds afterwards on screen. This cannot be fixed, and the best you can do is get used to the delay between performing an action and play defensively.
ISP-related lag refers to your connection being iffy, overloaded or otherwise unreliable. You might be able to switch ISPs, but it's a gamble as there's no guarantee it'll help. With this one you're likely to be SOL as well.

Diagnosing which sort of lag you have is important- often times, players will suffer from both graphic lag, and a little bit of server lag. The best way to tell is run different multiplayer games with different system requirements. For example, if you can play WoW with little or no lag, the problem is likely with server distance. If a graphically easy game runs, but a more intense game is jerky, you might need a more powerful computer, or cleanse your system of bloatware.

I suspect you may have an easier time if you clear up your lag issues or find a way to adapt. Otherwise, I agree with Juances- the game has ALREADY been made considerably easier in many areas. If you keep getting stomped outside of Tier 1, you need better equipment and more practice, usually the latter.