Authorization and Client Settings in PI

Seems like most are basis questions but i have not worked in basis, but let me see what i can help with.

1. Are there any standard authorizations that should be assigned to the developer.

Try with these roles:

SAP_XI_DEVELOPER

SAP_XI_DEVELOPER_ABAP

SAP_XI_DEVELOPER_J2EE

2. What client settings / role should be set in scc4 for default ABAP client.

Though not sure what default ABAP client exactly means. If default ABAP client means the client in which the users should be logging in and working and testing their scenarios, then the role of that client should be Integration Server and the client should not be 001 (as i think it is system copy client 001).

3. I'm running my SLD on SOLMAN.. I dont have a local PI SLD.. I am not sure if I need the PISUPER user on the Solman ?

Not necessary. Any user in SOLMAN will do but it should have role SAP_SLD_ADMINISTRATOR to do changes in SLD.

4. Do we allow developers to access the SLD ? for updating newly created PI z-developments etc ? If yes, do we create an additional ID or provide him with PISUPER password ?

It depends - sometimes developers are given sld access, sometimes only basis team maintains sld. But do not provide PISUPER password to developers, instead if needed, then create ids for developers in SOLMAN and provide their passwords to developers.