The Fairfield Grande (and all of our arbors and pergolas) are not meant to support anything but plants. In that regard, it is covered by a 20 year warranty against defects and you'll never have to paint it or stain it.
The Fairfield Grande arbor is designed to add beauty to your yard and support climbers such as clematis and honeysuckle. Any weight beyond that is not recommended.
To install in the ground, you will need to purchase either the arbor post extension kit or 4X4 posts, available at Home Depot.
There is no concern for snow load for the Fairfield Grande. We have customers that enjoy supporting their grape vines with the Fairfield Grande however it must be installed in concrete and even then, over the years as the vine gets bigger (and thicker) it will move the arbor.
The Fairfield Grande arbor was designed to complement your garden and be installed in the ground. It could be installed on a deck but we don't have any brackets engineered for that purpose. You may have some luck with Simpson Strong Ties.
Great question. VA84231 is our Fairfield Grande Arbor. VA84230 is the same arbor with an extra trim kit. The trim kit is a decorative add-on that included a short base trim and an extra trim around the top of the posts. Both versions are covered with our 20 year manufacturer's warranty and you will never have to paint or stain either of them.
Your 4X4 should extend at least 10" above the ground and into the arbor for stability. The bottom rail of the arbor comes in at that height. If you want to have more height, you can trim the width of the 4X4 at the end so that it will fit past the bottom rail.
You can bring the opening of this arbor down to 5'. We do not have a gate that would fit a 5' opening.
Because of how aggressive a Wisteria vine is it would be better to train the vine to grow up the side of the arbor rather than through the lattice. You will also need to make sure you keep your Wisteria vine trimmed so it doesn't become overlay heavy.
Yes, vines can grow between the lattice grids.