About your idea yeah that's the most reasonable and pertinent suggestion about morpho yet , and to make it even more interesting and newbie friendly have few extra things like this:
Things to put in HTML:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="<{$xoops_langcode}>" lang="<{$xoops_langcode}>">
<head>
<meta http-equiv="content-type" content="text/html; charset=<{$xoops_charset}>" />
<meta http-equiv="content-language" content="<{$xoops_langcode}>" />
<meta name="robots" content="<{$xoops_meta_robots}>" />
<meta name="keywords" content="<{$xoops_meta_keywords}>" />
<meta name="description" content="<{$xoops_meta_description}>" />
<meta name="rating" content="<{$xoops_meta_rating}>" />
<meta name="author" content="<{$xoops_meta_author}>" />
<meta name="copyright" content="<{$xoops_meta_copyright}>" />
<meta name="generator" content="XOOPS" />
<title><{$xoops_sitename}> - <{$xoops_pagetitle}></title>
<link href="<{$xoops_url}>/favicon.ico" rel="SHORTCUT ICON" />
<link rel="stylesheet" type="text/css" media="screen" href="<{$xoops_url}>/xoops.css" />
<link rel="stylesheet" type="text/css" media="screen" href="<{$xoops_themecss}>" />
<{$xoops_module_header}>
</head>
<body>
<!-- ## START OF LEFT ## -->
<{foreach item=block from=$xoops_lblocks}>
<{$block.title}>
<{$block.content}>
<{/foreach}>
<!-- ## END OF LEFT ## -->
<!-- ## START OF CENTER ## -->
<{foreach item=block from=$xoops_ccblocks}>
<{$block.title}>
<{$block.content}>
<{/foreach}>
<!-- ## END OF CENTER ## -->
<!-- ## START OF CENTER LEFT ## -->
<{foreach item=block from=$xoops_clblocks}>
<{$block.title}>
<{$block.content}>
<{/foreach}>
<!-- ## END OF CENTER LEFT ## -->
<!-- ## START OF CENTER RIGHT ## -->
<{foreach item=block from=$xoops_crblocks}>
<{$block.title}>
<{$block.content}>
<{/foreach}>
<!-- ## END OF CENTER RIGHT ## -->
<!-- ## START OF CONTENT PAGES ## -->
<{$xoops_contents}>
<!-- ## END OF CONTENT PAGES ## -->
<!-- ## START OF BOTTOM CENTER ## -->
<{foreach item=block from=$xoBlocks.page_bottomcenter}>
<{$block.title}>
<{$block.content}>
<{/foreach}>
<!-- ## END OF BOTTOM CENTER ## -->
<!-- ## START OF BOTTOM CENTER LEFT ## -->
<{foreach item=block from=$xoBlocks.page_bottomleft}>
<{$block.title}>
<{$block.content}>
<{/foreach}>
<!-- ## END OF BOTTOM CENTER LEFT ## -->
<!-- ## START OF BOTTOM CENTER RIGHT ## -->
<{foreach item=block from=$xoBlocks.page_bottomright}>
<{$block.title}>
<{$block.content}>
<{/foreach}>
<!-- ## END OF BOTTOM CENTER RIGHT ## -->
<!-- ## START OF RIGHT ## -->
<{foreach item=block from=$xoops_rblocks}>
<{$block.title}>
<{$block.content}>
<{/foreach}>
<!-- ## END OF RIGHT ## -->
<!-- ## START OF FOOTER ## -->
<{$xoops_footer}>
<!-- ## END OF FOOTER ## -->
</body>
</html>
With variations of this .. like the xo things i'll never use unless the ones i'm using will become obsolete. And with explanations of each one listed
xoops_footer prints the footer you set in admin, uname prints username and so on.
Then the css core stuff
#mainmenu {font-size: 12px}
#mainmenu a { display: block; margin: 0; padding: 4px;outline : none;}
#mainmenu a:hover {}
#mainmenu a.menuTop {padding-left: 3px; }
#mainmenu a.menuMain {padding-left: 3px;}
#mainmenu a.menuSub {padding-left: 9px;}
#usermenu {font-size: 12px}
#usermenu a {display: block; margin: 0; padding: 4px;outline : none;}
#usermenu a:hover {}
#usermenu a.menuTop {}
#usermenu a.highlight {}
.item {font-size: 14px;}
.itemHead {padding: 3px; background-color: #212121; color: #373737;font-size: 12px}
.itemInfo {text-align: right; padding: 3px;}
.itemTitle a {font-size: 20px; font-weight: bold; font-variant: small-caps; color: #ffffff; background-color: transparent;}
.itemPoster {font-size: 90%; font-style:italic;}
.itemPostDate {font-size: 90%; font-style:italic;}
.itemStats {font-size: 90%; font-style:italic;}
.itemBody {padding-left: 5px;}
.itemText {margin-top: 5px; margin-bottom: 5px; line-height: 1.5em;font-size: 12px;}
.itemFoot {text-align: right; padding: 3px;}
.itemAdminLink {font-size: 90%;}
.itemPermaLink {font-size: 90%;}
table {width: 100%;}
th {background-color: #ddd;height: 25px; padding: 5px;font-size: 14px;color: #454444}
table td {padding: 0; border-width: 0; vertical-align: top; }
div.xoopsCode { width:680px;background: #e3e9ef; border: 1px inset #000080; font-family: "Courier New",Courier,monospace; padding: 0px 6px 6px 6px;}
div.xoopsQuote { width:680px;background: #e3e9ef; border: 1px inset #000080; font-family: "Courier New",Courier,monospace; padding: 0px 6px 6px 6px;}
.outer {border: 1px solid #d2d2d2;}
.head {background-color: #ddd; padding: 5px; font-weight: bold;color: #fff}
.even {background:silver; padding: 5px;color: #fff}
.even a {color: #545454;line-height: 180%}
.odd {background: #737474;padding: 5px;color: #fff}
.odd a{color: #fff}
.odd a:hover{color: silver}
.foot {background-color: #e3e9ef; padding: 5px; font-weight: bold;}
tr.even td {background-color: #b8b9b9; padding: 5px;}
tr.odd td {background-color: #979797; padding: 5px;}
Again with little explanations here and there so a newbie won't have to start from scratch and won't have to waste time asking in forums how to display this and that in the theme and they will have more time available to actually build something.
Now unless i left out something from css then both from above makes you a skeleton XOOPS theme where one can add its truly creativity and that's as basic as you can get...one html file and one css file ;)