First, thanks for using the ROM. We appreciate everyones support!
Onto your question. The reason you cant just install these apk's via an explorer is because they are trying to install into data/app and HTC has protection on these which prevents that from happening. They will only install to and run from system/app. The HTCclockswidgets does rely on the weather stuff as documented in bloat.txt in post #2 (at the bottom of document under "special considerations").
I have 2 suggestions for you. First suggestion is, which clock are you looking for? There are plenty of clock widgets in the market that come in all shapes and sizes. One of my personal favorites is a 2x1 digital clock widget thats called "Digiwatch widget" and is free in the market. Also, what ...... you don't like the AC technical support clock widget we included?!?!?!?!?!?!?!?!?! Kidding

i know we all have our favorites but this one happens to be my new personal favorite. I was showing it off to all my buddies today, thanks again gbhil.
Suggestion # 2 It sounds like the LITE ROM may not be the ROM for you depending on how bad you want the htcclockwidgets. You may be better off downloading the full, then using root explorer to get rid of some of the crap. again, refer to the bloat.txt attached to post #2
Keep on rocking and we'll keep on rollin!!