The route map shows these stops. Halket and Forbes is about 250M from the Best Western. To return to the airport from the Holiday Inn, you can catch the 28X at a stop near 5th and Tennyson. The stop on Craft, near Forbes is the closest outbound stop to both the Hampton and Best Western. The asymmetry is due to the fact that 5th is one way between Bellefield and downtown while Forbes is one way from Bellefield and Craft.
Passes are available at a number of places near the conference hotel.
The bus system has a web site that contains information concerning schedules, fares, etc. While each route is supposed to have a map available on the web site, some of the map URLs generated for the schedule pages are badly formed. If so, removing the blank and trying again will take care of the error. This seems only to occur on routes without a trailing letter, e.g 52 and 500 provoke errors while 54C, 4U, 71A, etc. If you have questions about the bus system, let me know.