To an extent, yes, I don't know if difficult is the word because innovative stuff is readily available the parks are just so risk averse. It may not be as cost effective on paper in the short term to risk an innovative attraction. The big parks could buy S&S Axis coasters, RMC T-Rexes, or Mack Xtreme Spinners, they just don't. Instead they put in the reliable but fairly vanilla B&Ms. The result is that people are pleased but not wowed. "Pleased but not wowed" seems to be the industry trend of the last 15 years or so. By playing it safe the parks actually run the the risk of becoming stale. Innovation was always required in the past rather than optional.

I think you answered your own question.  Once the waterpark closes each day, families tend to vacate KK.  In the past, that left the later hours predominantly filled by teens.  And its no secret that KK has had more than its share of "issues" with teens in the park.  I'm sure its a multi-tiered decision, but I guarantee that was a large factor. As for "theme park" vs "amusement park" - its pretty clear what the Herschend strategy is with this park.  Just watch their latest construction video (part 1) - skip to the thirty second mark.  

I have to agree with you on this (although from the perspective of someone much younger). It's much more difficult for parks to design and build anything "new" these days without breaking the bank or being gimmicky. We're still dealing with the results from the Coaster Wars as well, so a lot of enthusiasts still have expectations that can never feasibly be met. I think Kings Island in particular could innovate more by adding advanced theming to their new rides until they are back in a position to install another "first of its kind" or similar.

I think a lot of the issues of security/fights/etc. happened later in the evening. While these issues could happen at any time, it seems as if the later it is, the more severe the issues become. So trying to keep it "family friendly," by reducing the risk of issues later in the evening.

Can you expand more on how changing the hours helps to define a park more as a "family theme park" as opposed to an "amusement/thrill park"? Is it in the fact that families might leave earlier in the night compared to those who go to an amusement park? The line between "amusement park" and "theme park" is very blurry at this scale of company. The new Six Flags lists all of their parks as "theme parks", despite only having a few that could actually qualify with Canada's Wonderland, Fiesta Texas, Kings Dominion, and Kings Island. A few other SF parks could probably also qualify for the title (maybe CePo and Caro) but the Six Flags brand is pretty much "generic amusement park". Other regional parks like Dollywood and other pre-Palace Herschend parks definitely qualify because of their abundant theming, but they also have similar lineups to the Busch parks in terms of balancing theming with thrills.