Elise is incredibly awkward to play. Her cooldowns are too long. Her caster spells are not very useful except for web. Vs any other character she falls behind very quickly. She can't cast web while in spider form, how does that make sense? Her rappel spell is neat, but unuseable.
I think you need to play her more and understand her kit. Aside from some farming issues in the new season, Elise is really fluid and is doing well in Korea right now.
Elise is actually very fluid to play and rappel is one of the best tools she has in her kit! As soon as you play her more, you'll get used to cooldowns, and if you're really having a super tough time on it, some CDR runes might help you out (Though I'm swinging to the opinion that AP blues are better than cdr ones)
A lot of that awkwardness just comes from not comboing or timing cooldowns correctly. Some basic combos:
Basic burst combo:
E -Q - W - R - Q (casting Q first allows for the full amount of damage since it deals more damage the higher HP someone is)
Basic burst combo (from longer range)
E - W - Q - R - Q (casting W first allows the travel time between the spider and your target, you should still have time for the Q to hit first.)
Use spider W and some AA's before Q if Q will not be enough to burst them very low (Such as if they have 50% or higher health after your combo) as spider Q scales off of missing health, so it's essentially an execute.)
Since you claimed that rappel is "neat, but unuseable" here are some general useful reasons to use rappel!
To close the gap between a fleeing enemy and yourself.
To reset tower aggro after a dive, especially if you can get out of range on the back of an enemy minion.
To escape being chased. Either by rappelling onto an enemy minion if there is one far from your pursuers, rappelling onto scuttle, rappelling to a monster camp, or an enemy in front of you and your pursuers.
To get from camp to camp faster by rappelling over wall.
To dodge incoming abilities. (Syndra Q, Vi Q, Hecarim ult all come to mind.)
To cancel out or avoid the damage of the ults of certain champions (Zed, Fizz, Cait. This requires proper timing.)
To easily access the backline of a team.
There are certainly others, but those were the first that came readily to mind, and the uses I use most often when playing the champion! Hope that helps :)
