Hi,
Thank you very much for your kind words, it means a lot!
Okay, for these customizations I would suggest the following:
– The result groups can be altered via the asp_result_groups hook. This lets you add/change any current result groups when the grouping is enabled.
– For the the associated product tags, it is probably sufficient to enable the search in taxonomy terms. These terms are automatically placed in the “other” group. You can of course move/change that via the filter suggested above.
– To customize the layout I always suggest sticking to custom CSS only whenever it is possible. For changing parts of the layout of each result you can check the advanced title and content features.
– For even more in-depth changes the results templating system is also available.