Joomla 2.5 customized calendar per user plus temperature set

Good morning,
I want to set:
1. one private calendar per user in Joomla 2.5.
2. and on each calendar I need to allow only these events: timestamp on heating system on/off + temperature target value (no other value allowed in the event rather than a decimal number, like 22.5 or so)+location of the sensor from a browse ($location in database).

From what I've read already in your forums, I understand that point 1 is already solved but not free, so I need a silver membership. And I understand that this membership covers unlimited number of calendars along unlimited time, and full support along 6 months. Please confirm.

Regarding the 2nd topic, what I would do is:
- Set heating system on as an event start and heating system off as event finish date-time (done).
- Is any additional coding required for setting into an event only a numeric value and avoiding any other input? Is it an already available add-on?
- I assume that extra coding is required in order to link the 2 inputs in the event to an already defined variable ($temperature for input 1, $location for input 2 of each event) in my database. Would help on this specific topic be covered by the membership support or extraquoted?

I already have these inputs coming to my database from website forms, but I'd rather have them coming from a visual way instead, using a user-friendly private calendar for each user.

I understand JEvents as appropriate for this purpose, but otherwise please refer to the proper module/API.
Thanks,
Javier