That's a lot of questions, and the overall answer is, "it depends."
Moving your data and design from one CMS to another is almost always going to be a lot of work directly in the database.
Does WP and Drupal lock you in? Yes. You can't, for example, use a WP plugin in Drupal without serious re-coding.
You can add special features to both WP and Drupal. There are many free and cheap plug-ins available for both. Custom coding for both platforms takes significant PHP and database skill.
when people upgrade to programs like Drupal or WordPress, how does it affect their Dreamweaver usage?
People who are not trying to alter WP or Drupal probably have little need for DW, but if you are trying to make code and even theme changes, then you may well use DW as a development tool.
Dreamweaver is a tool used used for pre-launch coding.
Drupal and WordPress are frameworks for creating CMS sites. Once those frameworks are installed and running on your remote server, you won't be using DW to edit the sites. It's all handled online through your Drupal or WP dashboard's admin panel.
If you're knowledgeable about code and more specifically how Themes work in Drupal or WordPress, you can customize the Themes with Dreamweaver to do more.
Start with a Responsive Theme either free or commercially purchased that fits most of your requirements. If your Theme lacks functionality, chances are good that an extension or plugin is available to fill in those gaps.
Drupal is for seasoned coders. It's not simple to learn but you can do a great deal more with it.
WordPress is much easier to learn.
There are many pro's and con's in using one of the big three CMS frameworks, too many to list here.
I tend to stick with my own creations for bespoke applications.
This site should help you decide. Take a special look at yii.
Wow, lots of things to think about. To be perfectly honest, my hunch is I'll never make the switch because I'm too locked in to my own designs. I certainly wouldn't upgrade to any CMS without hiring someone to help me install and configure it. But I suspect I'd need a lot of paid sessions to get all my projects translated to Drupal/WordPress.
Which CMS have you been using up 'til now?
I designed my own years ago. More precisely, I put one together with a lot of support from forums and have been refining it since them. I've come a long ways, but it's still pretty amateurish; I'm primarily a writer, and there just isn't enough time in the day to research and write articles and learn web design, programming, etc.
Many commercial servers provide support for Express installation of WordPress with cPanel or some other server app. If your server supports this, you can install WP on a sub-domain or site folder like /blogs. Try it and see how you like it. If you hate it, you can delete the blogs folder later without effecting your current site(s).
Hostagator has a tutorial for installing WordPress using Fantastico's express WP installation widget.
but the obvious problem was "What happens to all the other sites if the main site goes down?
Goes down because the server hard dirve failed, the server got hacked, or because you wrote code in a class that broke the system? Not really understanding the issue and how that relates to the issue of custom cms vs Drupal/WP.
I think my current server has Fantastico. I actually installed WordPress a year or two ago to try it out. Setting up a simple WordPress blog is a cinch, but carving an entire site out of a WordPress installation is a far bigger challenge, of course.
I went to a WordPress users group meeting a few weeks ago, and one of the advisors advised us that WordPress isn't easy, even though it's advertised as user friendly. Ironically, some of the hardest questions to get answers to are the easiest questions - questions everyone thinks you should know the answer to intuitively. I've found it hard getting some of my simplest questions answered on forums.
Anyway, I decided there's no way I'd upgrade to WordPress or Drupal without hiring someone to help me with the installation and basic configuration and set up.
It isn't directly related to Drupal/WordPress; someone just asked me about my CMS, and I was commenting on it. I was originally contemplating a similar WordPress or Drupal installation - one that somehow linked several sites together - but I can see now that would be a mistake.
I'm with Rob here. I don't see how or why having multiple sites running off one WP or Drupal installation is a mistake. A lot of people do it without any problems. It goes without saying, you must be vigilant about reliable recovery backups -- site files and MySql data. In fact, there are WP plugins that automate this task for you.
I was originally contemplating a similar WordPress or Drupal installation - one that somehow linked several sites together - but I can see now that would be a mistake.
Not a mistake at all.
Just have a robust recovery strategy in place.
Wordpress (where most of my experience lies) offers good multisite capabilities
Couple that with a decent (commercial) backup solution such as Vaultpress VaultPress + Multisite | VaultPress | Help