I thing you don't really understant the limitations ...
1. Amount of crafting tables (those which gives bonus) is about the classes not about the amount of crafters and every serious crafter will need to level all clases anyway hence having small house will cut the number of avialable "bonus" clases to half. Also I doubt you'd be able to place the crafting tables in your personal rooms but I might be indeed wrong as not much info was release about this yet and even if so the cost would be very prohibitive - they're all in range of millions (or at least several hundres of thousands) still on most of servers and remaing for a while as 3 star housing items and once you'd be able to craft them yourself you'd not need them anymore.
2. In regards of gardening - it's not about the amount of people "planting the seeds" - it's all about the time - currently the gardening is one of the huge income sources for FC house owners and having 2 or 3 patches instead of one will double or tripple that income or variety of items and seeds gathered. Considering each round of plants can take anything between 3 and 7 days to fully grow (depending on type of plant and amount of the feritilizing) and the fact that you might need to interbreed up to 3 times to get the high level seeds for most demanded products like Glazenuts, Broombush or Jute you're looking at about at least 20 to 30+ days to produce a few of one type - if you want all 3 it could be easilly over 3 months just to get those and so on ...