Currently i am using Vtiger 5.x and have hit several barriers in building custom modules via their module builder. Without actually hacking it, i can't meet my businesses needs. Additionally, Vtiger is not as mainstream as SugarCRM and if we were ever to bring in developers to do work, add modules, or integrate our website into the CRM, Sugar is an overall better choice.

My questions are related to customizing SugarCRM CE in order to accommodate sales leads, opportunities, quotations, sales orders, price books and products / services. Additionally, we have another arm of the business that needs to manage a publication circulation, distribution, cost analysis, and subscriptions.

I have found on SugarForge, modules that have been pre-built to tackle some of these needs, mostly taking care of invoices, sales workflow, and reports, but a custom module that manages publication distribution will need to be done in-house.

My questions are:

1) how much coding experience do i need in order to custom build a module that will map records from different modules? ie. account name mapped to a new module that is managing distribution information for that account

2) when working with pre-built modules created by 3rd parties, what should i expect when it's time to upgrade to a new build of SugarCRM? Will my CRM break at every new build or release?

3) when working with custom modules what are the best practices when customizing elements of the CRM? ie. if i want to build out additional address fields for an account, should this be done before or after i load pre-built sales modules? also, how well should pre-built modules handle custom added fields?

4) any good primers or suggested reading before i go wild and start building custom modules?

many thanks in advance!