I handcode a lot of php and html but I use Dreamweaver in the "code view" as it highlights php blocks of code and makes it easy to see if the syntax is incorrect e.g. if i forget to put inverted commas around a string, the n the string will not be shown in red font as opposed to black/blue for php code.
To be honest, with php, you will at some stage need to return a webpage to the user from a php script and Dreamweaver cannot do this very well, so you will probably need to handcode the html within php code.
Hope that doesn't sound too complicated but YES, you should learn html in detail.
Hope this helps.
Stoney