Its not a NODE persay, its a custom template designed to look similar and uses core xenforo CSS (same CSS used for the Node layout). When enabled, you can locate it above or below the forum node list.
This is the custom template: nflj_sportsbook_node_list
Only Sportsbook uses this template, so its safe to modify it to however you want to (you can convert it into something completely different if need be).
I use the Node ID of 9990 and SB9990 for where things like the Node Icon (that require an ID) have an actual Node Id (even tho its a simulated node). You'd mange the Node Icon in the same way that you manage a regular node (there is plenty of information at xenforo.com on how to do that).
As for the wording of stuff. Sportsbook is 100% phrased, so all text is managed via the phrase system. The Phrase system has a search feature that can quickly find text and tell you what phrase it is. You can then edit the phrase and change the text to what ever you want to. The 2 phrases that you'll probably want to change are:
Phrase: nflj_sportsbook_the_betting_Parlor
Phrase: nflj_sportsbook_the_betting_parlor_descritption
how often does the number of events/wagers/outcomes update?
Those are stored in CACHE so that you don't have several queries run on every single page view on both Forum Home and All Sportsbook Pages that display the stats block. CRON updates those once per hour. You can change that if you need to (and you can also run it manually). The CRON is Sportsbook: build stats cache for Sportsbook Statistics sidebar block (All sportsbook CRON's start with Sportsbook, so you can filter the CRON list to see all CRONS related to Sportsbook.