custom programming integration

I am going for an interview next week with a ERP software company. We are using this software with my current employer and i understand everything about the software and database.
From my discussions with the Gm on the phone the position would entail customer customizing of their canned software. From modifying their own crystal Reports, creating new reports (access and crystal), to creating VB apps to integrate their software with other third party apps such as integrate ERP software with UPS worldship, or ACT!

I do have expierence with report customization and creation with Access for my current employer (3 years) so i do understand database and have made numerous forms and reports four our needs.

A few questions.

ive just barely glanced at crystal. If i know access how easy is crystal? im assuming that is i know access crystal should be a breeze.

As far as VB integration apps. I have not had to do this currently and have not used VB since college except in some ASP stuff.

So has anyone out there had to do this in their work?

There is a SDK that they provide their customers using VB and XML to connect to thier database. Would this be the way they do it internally?

Would you just make two direct datasource connections one to erp and third party software, manipulate data, then insert, modify, change ect to different databases?

Any help would be appreciated! Thanks!