Trust me, I've been trying to keep my guildleves down, but I'll be reaching 99 in a week or two in spite of everything because raw exping is better in parties, so I only do it on crafts or for guild marks.

Sounds to me like you want quests such as the the ones where you turned in 4 bat wings to the guy in Sandoria or rusty buckets to the man in bastok. Get a quick task and a slight reward.

Thing is, that's the exact idea that Guildleves is based on. Though I got to admit, I hate leves, because they're so generic.