I'm one of the developers of VizAlerts and in my day job I'm a Tableau & Alteryx consultant at DataBlick. Coming out of my latter experience, I want to set some expectations:
When an organization wants to keep doing the same thing (like delivering Excel workbooks) what they are saying is some form of "We don't want our business to change."*** and I've found that those organizations are the hardest to satisfy with Tableau implementations because Tableau has never been designed or developed as a tool that can 100% replace existing BI solutions while also adding awesome new functionality. In this case though Tableau and Excel can both generate similar-looking charts and graphs underneath they are very different tools, they are effectively "apples and oranges" when it comes to the underlying rendering mechanisms and file formats.
Getting to your question #1: Distributing a Tableau workbook as an Excel file while keeping field order, presumably sort as well, color, and font for a crosstab view really means "convert one or more views from the Tableau workbook to look like Excel" and that means "download the Tableau workbook XML, parse the XML, get the data as well, and then generate Excel XML" from that. There are assorted technical reasons as to why this is challenging and I don't know anybody who has tried to do that either as a commercial or open source/free software project.
The good folks at Starschema have built an Excel extractor tool Tableau to Excel: our free Tableau Extractor tool -Databoss that will do basic conversion of Tableau's CSV output (I haven't tried it yet) but it's not integrated with VizAlerts. Metric Insights http://metricinsights.com/ is a commercial product that takes data (not views) from Tableau (and many other sources) and can deliver XLS as an output but I don't know the level of formatting for those outputs.
So with all of this having a same-same Excel view of a Tableau workbook is not on our roadmap. As for question #2 we would like to add the ability to at least keep field order for a CSV download, have Excel workbook as an output option, and put multiple CSVs into the same Excel workbook, but we are a volunteer-based project therefore I can't give you a timeframe as to when that would happen. If you happen to know any Python developers with some extra time we'd love their input!
*** If possible I'd take a deeper look at what the outside business partner(s) are doing with these Excel files and see if Tableau can deliver them what they need instead of using Excel. There are various cases where I've seen organizations deliver Tableau packaged workbooks (that can be opened up by Tableau Reader) and/or add the outside partners as users to Tableau with their own custom views. And none of that might be feasible at all given all the requirements and Tableau+VizAlerts might not be the best tool for the job.
Thanks Jonathan for your reply, we will see what we can do.