It is not compulsory for you to use the 3 package features. You can turn it off but it is advisable to use, it will make it easier for buyers to understand the services you provide and choose the one that is suitable for them
Message fiverr support to help you cancel the order so that it will not affect your account.
Even if the buyer increase the money, he/she may give you bad review
You can check the categories and subcategories of your gigs and see they are not the same. if they are the same, you will only see one type of buyer request but if they are not you will see multiple buyer requests