Any ideas as to what I should do - moving to a different program to iWeb isn't really an option due to skills and money.
Unfortunately you're going to continue to have problems with iWeb as it's not designed for the task you're trying to do... It really should be left to the realm of the home user who wants to put a few photos of the kids on the Internet so the relatives can see what the family is up to. While it's very simple to use and actually comes with some reasonable templates - it's not a professional tool by any stretch of the imagination.
I'm loathed to say this as I've seen this sort of question/response degrade into a "I'm better than you because I use <insert name of text editor>" in far too many internet forums....
If money is the issue - Your best bet is to develop your skills and learn HTML. There are some great resources on the Internet that are both free and easy to understand (this forum is a great place for advice), but it will take time and patience on your behalf. As for software to use - I will at no point suggest notepad, while it's free it's certainly not the best thing around and there are other cheap/free options that will colourise your code, suggest tags, number lines and all these wonderful little features that keep you from having to track down the attributes you can't remember in a book you're using to stop the desk from wobbling.
I come from the days when coding by hand (starting with notepad and then moving to BBedit) was the only option. The WYSIWYGs that were around were truly horrendous and I've found this is a fantastic skillset to have when it comes to all the issues with developing HTML email. To get things looking consistent with email having the knowledge and ability to control everything that is appearing in the code will stop you from bashing your head against the wall.
The more expensive option is to stick to design in a program like Photoshop and once you're happy with the design get a developer (there are plenty of them that would be happy to help you for a fee around the forum) to put it together and test for you.
Another middle-ground option for you might be to learn to edit the templates provided by CM by reverse engineering them. Start with editing the graphics and then move onto changing colours and fonts etc. Many brilliant web designers/developers actually started learning how to write their own HTML this way.
Jayneylou - I am inspired by your methods!
I also used HTML some number of years ago and am not so versed in it at the moment. I have found that you can learn a lot looking at the script/source, and it is possible to tweak things from that side and end up with a functioning template afterwards.
Still learning :)