@NIcolas
Did you try the module "base_phone", which is part of the OpenERP-Asterisk connector that I develop and is independant from Asterisk (for OpenERP 7 and 8 only) ? This module will add "tel:<phone_number>" links on phone number fields. This should work for click2dial with you SIP softphone or the OVH PC software for click2dial. In fact, when you look at the code in lp:openerp-asterisk-connector/7.0 or lp:openerp-asterisk-connector/8.0, you will find 7 modules independant from Asterisk (all the modules that don't have "asterisk" in their name) and 2 modules which depend on Asterisk.
For the popup feature, you should have a look at the module "base_phone_popup". It is not easy to setup, but it is independant from Asterisk. What you will need is to develop a small glue that will call the OpenERP server via XML-RPC when you have an incoming call and pass him the logins of the users that need a pop-up as argument. If you want a sample script to call the right OE Webservice, have a look at asterisk_click2dial/scripts/openerp_popup_timeout.sh and asterisk_click2dial/scripts/set_name_agi.py