Sara, is this still the French guest? In France most people have flatrates on Internet at home - it's pretty difficult to get a contract for a landline which does not come via a box "all in" : Internet, phone, TV and all illimted. If you do not have that, just tell him that your Internet is limited. Maybe you can buy more GB of data for the months? We did that at an American friend's place, where I had to set up all her computers, tablets etc and use Internet myself. Calling the operator in advance to add 5GB was cheaper than to let the use run up paying by the MB.
You should be able to follow the use and your invoice online - I suppose video calls and video downloads are not recommended if you do not have a flatrate. And he should logg off if he plays publicity financed games on the phone or tablet, they are huge consumers of data.
As for the use of the common space: you can limit that in advance in your listing, but it will reduce your chances for further bookings.
I see two ways to react in the ongoing situation:
- have a discussion (probably to be repeated every few days) about use of the dining room and agree upon hours where it is off limits to him, if you use it or not, and hours where you cede it - best to coincide with hours you are out of the house to limit the impact on your nerves.
- make it subtly inconfortable for him to be there. Like a huge puzzle, accounting with all the bills or cookie dough spread out on the table. (You would have to share some cookies then, maybe he finds jigsaws interesting, but nobody but my parrot loves piles of bills and tickets).
The more reasonable approach is to talk to him. If he planned to stay out more, but his plans changed and he does not need to, it's understandable that he wants to stay home more and the room is very small and not very comfortable to spend the day*. On the other hand, hosting in a smaller space onsite, you need some privacy too and the use of your place as you wish to use it. I found that it is not the sheer amount of hours a guest may be home that is bothering but not knowing when you will be alone or the sole user of your "common" rooms. That gets under your skin to a point, where I was really furious to go out to leave the lingering guest some privacy and returned two hours later to discover the guest left at my heels and returned before I had time to hang my jacket into the wardrobe. Had we coordinated our plans, we both would have had 4 hours of paece.
Now I ask my guests every evening or morning what their plans are and when they will be out of the house. - do that nicely and it passes for interest into their wellbeing, do it too nicely and you get a flood of stories about their day up to the lifestories of their whole family.;-)
*If you remember when you first joined groups, some of us counseled you to make your bed more couchlike to give the room a feeling of a living room as well. I don't see your space from the Community Center to check for changes, but sometimes it's a subtle change that will decide where people stay. My guests stay in their much smaller space, even if I invite them down, because the bed transforms in a very comfortable couch with large extra pillows, a daycover to sit on, a plaid to cover your feet and a wall to lean to. Ikea had laptop supports that you can place on a couch on sale, so I added that.