Consulting internship for IT career?

I am a computer scientist student in my senior year. At the moment, I’m doing an internship at an automotive-OEM and discovered that I lack several skills:
- Knowledge about manners, hidden rules and business behavior (business lunches, office, how to treat clients, how to write mails, how to properly introduce)
- Advanced Powerpoint and Excel skills
- Understanding of the political flow inside a company
- Basic understanding of economic practices (influence of mother companies on daughter ones, joint ventures, decision making processes, strategic thinking, financing)

I already saw that this will limit me in my future performance and my boss already mentioned my limited PP skills.
My goal is to start in the IT department of a large company and rise to a leading role.
My idea is:
Do an internship in consulting and attack the aforementioned points.
I do NOT want to go into consulting in the long run, but sharpen my thinking.

My questions to the community:
1. How are your experiences in consulting internships regarding learning manners, business thinking for non-business students, PP and Excel?
2. How did consulting internship experiences help you in your non-consulting career?