We went this past Saturday for the day, we live about an hour away. Anyways, the weather was great. It was really really windy for May, but other than that, it was nice.
Right now, we're in the middle of some pretty nasty wildfires, and I was scared that it was going to be really really smokey, but there wasn't any smoke in sight. It really depends on which way the wind is blowing, and this time it was everywhere. It was pretty overcast on Saturday and looked like it could rain, but it didn't. The sun was hidden. I'm pasty pale, and even throug SPF 50 got a bit of a burn on my shoulders, but that's what happens when it's overcast ... I get lax on the sunscreen.
I don't know your dates, but if you're lucky enough to be in Epcot for Characters in Bloom, it was awesome. My daughter got to climb a playground rope thing with Wendy ... while Peter sat and talked with this little boy for like ten minutes. It was some of the best character interaction I've ever seen at Disney. Plus, you'll be at Epcot for the Flower and Garden Festival and it's BEAUTIFUL!
We didn't really ride any rides, just Nemo. We spent most of the day with the characters and checking out the different countries. When we went to MK after dinner, my dd finally decided to take her nap, so we were only there for about two hours. Soarin had a nasty wait at one point in the day, but Julie is to young to ride it ... and I didn't bother looking at MK since she was asleep.
About the bugs ... personally I've never been bitten while at Disney, but my mom got some nasty horsefly bites at Fort Wilderness. I think they're called Deerflies, or something ... they're really nasty bugs. She's the only one in our party that's ever been bitten by them, even in other parks in our RV. The love bugs are EVERYWHERE. They're harmless, the don't bite at all. The point of a love bugs life is to find it's mate and well, love. They get stuck together and fly around and then they die. They don't bite, and the only thing they hurt is your cars paint job. You can always bring along the insect wipes just to be safe, I'm an overpacker even on a day trip.
My only complaint was all the high school trips that were there. And I laugh when I say that since I ALWAYS went with my highschool choir. We had dinner at 1900 Park Faire, and they sat a 36 top of teenagers at the same time.

They were carrying on, running and pratically knocking over people. Scared Juliette to death. I ended up holding her in line at the buffett, and "accidentally" knocking them back. I've never seen kids run around like some of the groups there were ... but hey, that's what Disney's about .... right ?!!?!
Have a good trip!