So all these plans predate my entrance into the saga; and while I've looked over lots of posts and have a lot of random exposure to those plans, it's still a bit of a whirlwind for me.
Is it possible for some hardy soul to collect the list of things that were in Viscaria's plan, sorted according to "most important"/"kind of important"/"cool if" categories (best guess), into one post? pretty please 
The only, minimum requirements were Housing for the Tribunal attendees and a space designed to hold the Tribunal, which could also double as a place to hold the Tournament...
Minimal Tribunal attendees are probably ~100 magi and 3 or 4 attendants per magus.
However, given Mons Electi's proximity to other Tribunals, many more guest magi could be reasonably expected. You can make them pitch tents, if you'd like.
I will stipulate that Viscaria's Hubris has led her to some of the easiest things last, the easiest thing being the most important things, of course: The coliseum and the housing is not done. Baths[1], the bridge that Tranquillina mentioned only half finished is actually fully finished are the only things that are finished? IS that better? A ruling from me? If the troupe doesn't like it, figure it out. 
[1]The structure is there, but the plumbing and heating system isn't finished. It might even end up being a task asked of Roberto, or someone asks Marcus to do it. Marcus has excused himself from these meetings whenever the subject of the Tribunal has reared its ugly head.
and these are the things that the contract will cover. I would guess that Korvin would have a very angry Viscaria in his office at the point that Praxiteles begins putting up all the dorms ( following her plans) and finishing the Bridge. He will have to sooth her by saying she is doing the delicate work.
But basically, Korvin wants to guarantee that this part of the Tribunal will happen without him having to worry much.
Are the competitors set?
No one running Grogs through the Melee?
Not fielding a team for the Hastiludium? Canonically, Renaud is uncommonly good, but... shrug
I'd rather not putting the Grogs through the melee, just in case. We might need them to be fresh, able, and aware. If they get involved in the melee they could be compromised, it'd be easy for them to meet with accidents or incidents that take them out of commission.
With Tranquillina, Alexei, Roberto, Korvin, and Isen, I think we're at the max five competitors for the team (I didn't include Marcus because of the question marks by his name).
Fiona actually has a lot on her plate for Tribunal, or she might have considered the Dimicatio.
Marcus is a coenobite, competing on his own.
Can you just give me a vis charge for getting the sewer system done for the Tribunal?
I'm tempted to say that the sewer system is nothing more than a ring in the ground with a PeCo effect around it, with a sign that says "Aim here, please."
Do we have a map or a layout of the Tribunal grounds somewhere that I'm missing? (And,if so, can we put it on the wiki somewhere?)
I'm looking to see if we have a place that would be a good venue for the Tribunal Ball that Fiona will be putting together. (Yes, she's slightly ambitious here )
Ok, so I missed this ball question.
It wouldn't be too hard, to put down a wooden dance floor over the coliseum's field. Wood or marble are possible. and suitable materials for dancing. Creating ambient lighting isn't hard, either. When would the ball be held?
Looking at the schedule, it looks like the evening of the last day ("a day of feasting and celebration closing it all up") would be the most likely. Either that, or the evening of the last day of the Tribunal proceedings, but I much prefer the evening of Day 7.