Hello, Liger! Welcome to our community!
I can't speak from experience on Otakucon, but we are smaller than Sakuracon. If I remember correctly, we were a little bit over 6,000 total attendees last year. This year, we'll be in two different hotels, so I'm pretty sure that the crowd issue won't come into play strongly enough to possible damage any cosplay accessory. We're a pretty friendly con, at least compared to most other cons that get more than 4,000 (I'm kinda stealing a quote from our chair, but I know he won't mind).
Some info you may need to know: We're in Vancouver this year, Hetalia is REALLY popular here right now, there's a nice park nearby that's about 4 blocks in size, I believe the Saturday Market will still be running during this weekend, um... I can't really think of anything else to say...
I hope you do decide to come! I guarantee that your experience here will be a memorable one!