Micros is, understandably, pretty protective of the admin passwords for the 3700. The current version has 1543 tables, 685 views, 1781 stored procedures and 1367 views. It also has user defined data types with default and check constraints for most fields. Supporting the product would be impossible if end users and third party vendors were allowed to make changes. I've been writing custom stuff for the 3700 for 7 years, up to additional total and tracking sets, and haven't needed more access than the custom user has. You just have to re-think the approach sometimes.
A good way to know what you can access is by the table name. Anything that ends in "def", (micros.mi_def, micros.fam_grp_def, etc...), will allow you to insert, update and delete data. Anything that ends in "dtl" will not. You can't make changes to the structure of any standard micros tables, procedures, etc...
It seems like you're developing some kind of web based system to place orders into a 3700. You're going to need to learn their proprietary scripting language, SIM, in order to get the orders placed. This will emulate keystrokes that the users would make and push the order through POS Operations. Inserting data for an order directly into the database probably won't work. POS Ops writes all kinds of info to temp tabels behind the scenes to keep track of itself. The only place to find info for this is in the Micros directories:
\Micros\res\pos\bin\Simhelp.hpl and
\Micros\documentation\res\pos\sim\3700SIM_CompMan.pdf.
Two last points in case you manage to get one of the admin access.
1) The dba & micros user passwords change with every release, so if your planning on installing on multiple versions you'll need multiple installation programs.
2) If you do makeany changes using one of the admin accounts it will void you're customers warranty and/or service agreement. If an internal database error occurs, especially if there's 3rd party software installed, one of the first things Micros support does is translate the db log and look for suspicious admin logins.