It isn't "just two hours". It's a third of the limited time available to you within the precious 10am to 4pm sightseeing slot.

I don't plan itineraries that are bursting at the seams yet I still get up a lot earlier than you intend to in order to accomplish my own aims. I sincerely lack the imagination required to understand how you will manage.

Midweek in Hakone is like a weekend elsewhere. "Wednesday = closed" is just a rule of thumb for the slightly smaller attractions in this area. As a for instance; the Chimoto Yumochi shop is closed on Wednesdays. Thursdays is the other problem day, the Museum of Art is closed then.

At least you won't have to leave until quite late on Thursday, that makes a big difference to what you might achieve.