Urgent Help Needed

Hello everyone and thanks for reading! I am brand new to the forum "newbie" but if this forum is like the forum for my profession (RE appraiser), the help is usually priceless.
First, I understand that you might advise me to call in a professional, so if there is a member of this forum in the Orlando area, I will be happy to call you!
Here is my really big problem- All I wanted for Christmas was a new shower door (my home is approx 20 yrs old)
My husband was removing the frame from the old door and the tile easily came off the wall - I know big problem-been there done that once already.
We continued to remove tiles and saw lots of dampness and mold. To make a long story short, we removed all the tile from the shower and the sheetrock(looked like sheetrock-may not have been) which was also wet. We started removing the tile floor as well. My questions are:
1. Do we need to replace the shower pan? We found standing water in the pan (should this be draining to the drain?)
2. On the lower half of the shower we removed everything to the studs, what should we replace it with? There is green board on the studs on the upper half of the shower which is fine. Can we apply tile to this green board or do we need another layer of something?
3. How do we determine if the studs need replacing?
4. We removed the rotten moldy wood curb as well-it had a marble sill which I just hated (mildew collected underneath)-what should we replace that with?
5. Also running behind the copper piping to the shower head is an electrical cable-this just doesn't seem right (code????)
I wouldn't hesitate to call in the pros for everything, but my husband was laid off his job Dec. 1 and we are trying to do the best we can on a very limited budget.
I can do the tile work (my dad was a tile contractor), but the prep work to get to that point is scaring me. Any help or suggestions is greatly appreciated! (including what you think is a reasonable cost estimate if we have to call in the pros) Many thanks and Happy New Year!

shower

Cement board backing for the tile. There are drain holes in the drain assembly which could be blocked with mortar. If the pan was installed correctly, i.e., the drain flange even with, or below, the floor, then the water should drain out when the holes are opened. If the flange is above the floor, then a sub base of mortar should be put in that slopes from the sides to the drain, then the new pan installed. Only you can tell if the studs have deteriorated to the point that they need replacing. If you can stick an ice pick or awl deep into the wood easily then they probably do need replacing.

Sounds like some unqualified or uneducated person who didn't know what they were doing installed the tile if you've got sheetrock behind tile in the shower. Every wall where water hits should be backed with a moisture barrier such as plastic or roofing felt then a substrate such as durock, wonderboard, or hardibacker or any other material that water is not going to affect should be the wall to which the tile is adhered. You can start by scabbing on or replacing the studs as needed then go back up from there. The shower pan needs to have no holes and be totally water proof. I think the best you can do is tear out all the tiles and do a total re-install. As for the electric cable... I'd say it's not to code and not a good idea but it will not be a problem if it is well protected.
My shack mate is soon to have her RE license... I might need a little advice from you too! I've got two pieces of property that I need to sell and need the best dollar I can get from them. One is in a flood plain and has very high potential. It has 3/4 acre lot above this and is next to a golf course with 8 or so acres of bottom land and a creek running thru it....classed as timberland and viewed as worthless other than for farming.... I love it and it is absolutely beautiful and within walking distance of a new main artery to the interstate. I see very high potential here.....
For more really great tile info go here... http://www.johnbridge.com/vbulletin/index.php?

Thanks, more questions

Thanks Randy and HJ-So if I understand you correctly, there should not be standing water in the pan it should drain under the tile to the drain, correct? And your recommendation would be to replace the pan.
You are absolutely correct, the construction quality of this home is average at best, I am grateful that it is CB/stucco ..)

Question of the day-what are usual and typical charges for a pro to replace the shower pan and prep it for tile? Should I call a contractor or plumber or both? While I am on a limited budget (RE market soft lately ..0) I want to do this properly even if it takes some time.

As for RE and appraisal-Be more than happy to help, where are you located? Residential appraising is very local (we know our local markets and have the research tools for our area) Our forum-appraisersforum.com is a national forum with members from all over the country that do all kinds of appraisal work. They are a wealth of knowledge and are ethical, experienced, and will answer questions from the general public (like you so graciously do)
Once again, I thank you

Dona.... thanks for the link. I'll check it out as time permits. As for the pan... my opinion is simply that it should not leak. If it is dry under and behind the pan then it's doing it's job. Things & techniques vary greatly. Years ago they would have used a sheet of lead on the floor and up the wall 6"-12" but now it's usually some flavor of rubber membrane with mortar to form a sloping floor. As for the drain hj described... it's different from one place to another. I've never even seen a drain with weep holes he describes and I've done alot of showers and seen alot of shower drains.... like everything else in life... different strokes for diff'rent folks. When all is done and said the big question is "Does it work?"
As for that wire... I'd want it to have a swag or drip loop anywhere near water to help keep water from any connection.