Module development and code questions

I'm developing a content-type module which allows user to upload several files to nodes of that content type. I'm not sure how I provide the upload file field.
Currently, I made it to work via Upload module, but it provides upload field on all nodes editing screens, and I need upload field to appear only on node that is provided by my module being developed. I know I can delete that field on 'wrong' nodes in my module's code, but I feel this is not the 'right' way.

i would like to search users by certain profile fields. is the site user list module the best option?

i installed the site user list module. it gives me a list of users with their user id and email address. so far, it went fine.
i want a search to be performed by first name, last name and country of users. so i included these 3 fields on the settings page, but the display of the site user list page is strange with each data getting repeated twice. pls help. how do i successfully perform a search by my custom fields like country, first name etc.

Hi. I'm developing a custom search module form and i want to give users some abilities to change the way they can view search results.

First, i want give the users the ability to change the results per page they want to see, and also if they prefer to see all results in a only page.

i want search results to provide some links like "all, 10, 30, 50", being that numbers the results per page they shown

is there any module capable to do this? if is not the case, could anyoune point me in the right direction?.

I try to use Form API to wtite a code for a form which will update exiting info in database. With the help of Forms API Quickstart Guide. The form should load existing info into itself, then user makes changes and press Submit to save them, updated info should be passed to myform_form_submit($form_id, $form_values) function in $form_values array. The problem is that the function myform_form_submit($form_id, $form_values) recieves $form_values with unchanged values.

i have around 600 user profiles on my site. is it possible for an authenticated user to search another user in order to view his profile?
as an admin , i am able to perform a user search under administer>>user management>>search users .
can i make this accessible to authenticated users also? if so how?

I'm working on a website on which users can register themselves and use the features of the website after they have paid a fee. The admin of the website has to manually enable the accounts for which has been paid. At the moment it is being done like this: Newly registered users are blocked and as soon as their payment has been confirmed their account is activated. For this blocked users are listed on a page created by a specific module made for this website. This way accounts that have not yet been paid for can easily be approached.