Templates and customization

I've been customizing my templates lately, and I've been finding it a 
challenge. I don't mean to sound arrogant, but if I'm finding it a 
challenge many others will find it impossible.

Specifically, I just added code to the weblog entry form to render the 
categories in columns, because I have 50 categories. (Many of these are 
vestigial, created over the course of the last three years, but they 
still exist.) This added Yet More Complication to the templates, and if 
anybody in the future wants to modify this code, it's one more thing 
they'll have to worry about in every template. As a result I'm hesistant 
to submit the patch.

I'm thinking that "ideally", we want to pull things like the category 
listing into Python code, so that a template author just writes

$categoryEntry()

or something, and the code takes care of columns and such.

The problem is, the complication in the templates is, for lack of a 
better word, "real"; the templates are implementing real features and 
sometimes they are the best way to implement the features. I find it 
hard to articulate but if you read the templates over with an eye 
towards what what could be pulled into the Python code I think you'll 
see what I mean. The pattern seems to be something like

#if complicateBooleanDeterminingIfFeatureIsRelevant
<some potentially complicated HTML code>
#else
<some potentially complicated other HTML code>
#end if

and a theme may want to change either of those two HTML segments to 
"fit", so you can't suck those into Python code without loss of the 
ability to customize.

So, topic of conversation: Is it worth trying to simplify the .tmpl 
code, or is the flexibility too important to give up? I'm willing to 
start migrating code to macros over time as I make changes (starting 
with moving the category printing code into a macro as a 
proof-of-concept), but only if it's worth it. And I'm not sure either way.