Can an internal auditor involve or assist management in the implementation of recommendations?

Internal auditor  can only assure about controls and can give suggestions for the improvements in the organization systems, however they cannot take part in management decisions

Yes, one of the internal auditor main priority is assure the quality o the work process as it should be as planned for the system of work in all departments, during internal auditor works he will find some falls and risks of miss using the assets and the problems of process the recordkeeping.

He shall record this problems and notify the higher management to implement the work to avoid such problems and assure the most consume of the assets to reach the goals and improve the quality of the reports/  

- At the end of each audit, a report shall be presented for scrutiny and audit scope, methodology, findings and conclusions goals and includes, in some cases, recommendations to improve the program or activity under scrutiny 

i guess yes. internal auditor is the one who can judge your work accuracy. he is the one who can share and guide someone he is auditing if there is any mistake or need completion. and he is the one who submits audit report showing the person qualify for a recommendation or not.