Sounds pretty normal to me. They are growing and changing so much some times they just need a bit more milk. It could also be the heat, they need a bit more hydration when it is hot and want extra feeds.
As for the irregular feeds during the day, I know ALOT of women say their babies get themselves into a routine by that age, but my girl hadn't, and even now I'd say we had a fair bit of variation day-to-day. Again the heat could be causing some extra feeds. So to me it sounds normal but I get the feeling my 'anti-routine' baby is in the minority. Hehehe, probably has something to do with her anti-routine mummy!
Anyway, it all sounds normal to me!