Welcome to the forum!
I think what you are after is data-driven design.
InfoPath is an XML editor so it's particularly adept at dealing with dynamic data.
You just need to create a normalized data source and then add a data connection that pulls the values in and copy those to the main data source.
Great examples of this technique abound. Surveys, checklists, performance reviews, contracts - you name it - are all great examples of data-driven design.
For offline forms, there's an added challenge of the data connection since we assume the user is connected.
One suggestion here would be to store pre-populated XMLs that correspond to the different "models" and then just use SharePoint workspace to synch them down to the laptop. In other words, the form either contains all of the model info included in a secondary data source or you pre-fill some XMLs to have the data and save those for synchronization.
In the former case, you'll want to create a separate InfoPath config form that edits the model pre-pop info. Easiest solution here is just to save your main form in preview. Use the XML to design a new InfoPath form (Run->InfoPath Designer->Design from XML) and then just drag and drop the entire data source into the view. Use this form to generate the secondary XML that you include in the primary form.
Also, for offline, you will need to either email the forms to a central admin or have them submit when they go back online.
Of course, designing your form from Access will not support this data-driven XML design. Tightly coupling your form to a set of Access tables will complicate the InfoPath data-driven design process. I recommend submitting to a SharePoint (using CAML or qRules) and mapping that list to Access. Of course, you could also use our general DBXL web service to map the form's data to a SQL database and then DTS that to Access.
A few ideas ...