Good try in processing but pictures have no life to them.
Compositions are okay, I see foreground & background interest and intended main subjects, but emotionally it's lacking.
HDR is not about just increasing dynamic range, retaining detail in highlights & shadows, but to use that increased dynamic range to bring forth moods and emotions on what the place is and what it (would/could) feel like. Bring attention to the important areas and less to unimportant areas. Imagine having control over the sun, do you choose to light everything or do you select what you want lighted?
The most noticeable trend of the photos are that everything is bright. There is no play of light, no intended highlight, and no intended shadow. An overcast sky is good in a way, it helps to expand your creativity. Not every composition will work of course, so let's take the first photo as an example. You have overhead cover, naturally giving light & shade onto the path, vegetation along the path is unnaturally bright. I think we share the same conclusion on why it would make a good photo, it has the potential of being mysterious or dramatic under proper treatment. However, this HDR totally wiped that prospect out.
My advice is to study the scene once you've decided this would make a good photo. Decided which elements require an extended dynamic range and then expose for them. Bracket as little or as much as you need be it 3, 5, 7 or 12 shots. In photomatrix or which s/w you use, instead of dumping all in, select which files you want instead. Or if the s/w doesn't give what you want, manually blend them instead. Software operate in algorithms, it doesn't know how to manipulate a mood into what it's processing.
http://www.adventure-journal.com/2011/08/portfolio-alexandre-deschaumes/
This was shot in overcast conditions too and while I don't know to what extent HDR was used, maybe not more than a few exposures each, but mood and emotion is retained and notice how not everything is well exposed. Our Botanic Gardens is 180° opposite of those peaks but the thought process is the same.
Sorry I didn't intend to write so much and make it like a critique. Must be suffering some withdrawal symptoms.
Continue having fun shooting, cheers~