First of all,
to the forums. Hope you enjoy your stay.
With respect to your questions, I have answered them below:
Well, some of the hosting providers offer more resources i.e. disk space, bandwidth etc. with the Business hosting packages in comparison to a Personal hosting package. Also, some of them do offer 100% uptime guarantee with the Business hosting package
Yes. If the resources and features offered with the Personal hosting package is sufficient for your business website, you can surely consider a Personal hosting package to host your business website
Generally, web hosting providers offer shared SSL certificates for free with the hosting packages and charge for dedicated SSL certificates as they have to pay for it, however, it might be possible that some of the hosting providers charge for shared SSL certficates also :(
I would suggest you to confirm with the hosting provider before you choose a hosting package with the hosting provider.
Please feel free to post if you have any further questions.