You can use both the left and right mouse buttons to perform regular swings and power swings against objects at the same time (just hold down both buttons). Even with 0 stamina you can chop down a tree in less than half the time as just holding left button, same with rocks, etc.
I played with some friends in coop last night, up to day 11. Our 7 day horde did not spawn at all. In fact we've noticed that day 1 has by far the most zombies, they are just all over the place as we rapidly attempt to run to each other. By day 11 we saw 0 wandering hordes, 0 night hordes, and even walked into a fallout city and only saw a single zombie anywhere in the entire area. Sounds like something has gone wrong? Also, we've never seen the chicken/bear hordes or anything like that from the first post of this thread, are those still in the game?
In terms of balance I'd just like to echo what someone else was saying before about the mod being very confusing with unlocks that give you absolutely nothing because the thing you just unlocked is hidden behind a gate you didn't know about. Even right in the beginning of the game with wood spikes you need a tool to 'finish' them but don't have access to any tools for 7+ days unless you get a lucky drop. 5 months ago we played till day 50 or so and after that experience and having restarted 4-5 times in the last week (limited # of deaths between us) our expectation of any recipe learned or skills purchases is that we won't be able to do anything with them until much later in the game. Some of this is UI related, recipes requiring a bench but there being no indication that a bench is necessary until it's already purchased and some of it is simply obtuse like wood spikes which are craftable on day 1 but not usable until day 10 or more in most circumstances.
There are so many things in the mod that's it's just impossible to remember everything so making things more intuitive would be a nice quality of life enhancement. For example the spikes could be functional immediately but AWFUL until upgraded with a tool and many of the skills could reference the specific bench needed before purchased, etc.