Go to App > Dashboards > Select the dash to be remove > Delete button bottom, rename there as well.
No, sorry you have to do it.
Not necessarily. I have a dash that is just for battery reading. So all my contacts and motion sensor and such are on it, but they all use the "battery" template, not the "default"
Nothing in Dashes auto sort (thankfully) you put things were you want them. Color changes can be made in the templates or as Custom CSS. I do not fully understand you height issue, but you can change them when ever you want, but yes you have to reorganize as needed.
Some of you "view" issue might be view port relate not design related. See this post I just answered about view port sizing.
Also know you can make size adjustments to fonts and such in CSS if needed. This dash colxrow 60x22.
