You can voice your suggestions and ideas for Office development to Microsoft through the Office Developer Platform suggestion box. There you can submit ideas and vote for what you want. Please check out the link below. This link also has links for SharePoint development and Office product suggestions.
For questions you can use Stack Overflow. Here you can find answers to many problems. One thing which is not apparent to those who use it is that many of the people who reply are from the Microsoft development teams which build the Office APIs, from those who write API documentation and support engineers and API specialists. This is a great forum site.
If you are a Premier customer, you can also file for a Design Change Request (DCR). However, also consider also using the suggestion box. A DCR is used to push for a change hard due to a business need.