Absolutely, but these types of changes are generally very ROM-specific, so you do not want to flash mods from other ROMs to your CM7 phone. It will have to be built specifically for that ROM. For example, the battery icons are in framework-res.apk if I remember correctly (at least on the Sense ROMs I have messed with like MikG). There are XML files that have to be tweaked to tell it which icon to display at which percentage level, as well as the actual images themselves. This .apk file controls much more than just those battery icons though, so flashing one from another ROM will at the very least change other icons besides the battery icons. Most likely it would just wreak havoc though and possibly screw up the entire notifications bar. That's why you always backup before flashing anything though.
I haven't messed with CM7...I had so many little issues with it that I have given up for now. You probably want to start with the CM forums though:
CyanogenMod Forum
By the way, I highly recommend ditching ADW for Go Launcher EX. It is fantastic, and is highly customizable. You can even customize one particular icon for an app on your home screen (or in Go launcher's dock). Or you can install a theme and change every icon at once. You can also change animations and so on -- it's unreal how awesome it is! I use a few Sense widgets though so I had to find replacements for them in the market (which wasn't too hard):
- Fancy Widgets to replace the clock/weather widget. Works like a champ -- tap the weather to see the extended forecast, tap the hours to enter in the alarm clocks settings, and tap the minutes to get into the widget settings (you can change themes, transparency, etc.).
- Android Pro Widgets has a calendar widget that is very similar to the Sense calendar. It also works like a champ. If you want to see events from Facebook you can export your FB calendar to your Google calendar. This is a decent post I found. It's essentially the same steps I took when I tried it:
How to Export Facebook Events to Google Calendar
- Elixir2 (and the corresponding Elixir2 widgets) for the 4G/Wifi/Bluetooth/GPS toggle switches. I preferred mine on the home screen instead of being in the notification tray so I disabled that in CM7 and just used Elixir. I added a 5th widget to it too -- so I could toggle between normal/vibrate/silent ringer.
I also think the default Android dialer sucks so you can check out Go Contacts Ex. It has a dialer that functions much like Sense. Also, the default Android keyboard is terrible so I would recommend you check out Smart Keyboard or SwiftkeyX. I prefer smart keyboard myself but either one can be highly customized to meet your needs.