Is a 1/2 bad on my first NCOER?

You need to look at where the 1 and 2 fall in the rating , both are still successful and superior. For a first NCOER that's not bad at all, I think your rater did you justice by letting you know there is room for improvement.
One common mistake for many raters is giving someone 1/1 when they don't truly deserve it and the rated NCO often items feels they are on track when in reality they need to improve somewhere. Then the next rater gives a lower more realistic rating and the NCO feels slighted.
A 1/2 is good even a 2/2 would be good for a first time report.
Think about who you are rated against, it's not the entire Army. If you are a squad leader you are compared to the other squad leaders in your platoon. A competent rater knows that out of three or four squad leaders they rate only one can be among the best, that's your competition.

SSG (Join to see) - the purpose of the NCOER is to help you see yourself - your ability to perform and improve yourself, your organization and your peers/subordinates.

Honestly, the Sr Rater portion ratings - the 1/2 you speak of, are totally irrelevant in your situation - you are a young SGT and this NCOER will be so old by the time you get looked at for SFC, that they won't even go back that far. Additionally, the Sr Rater portion is not going to be what gets you recommended to go to the SSG board - your performance/potential is.

Focus on what your rater says you are doing well and the things you need to improve on - that is the benefit to the NCOER.

No that is not bad on any NCOER

Successful, and superior ratings, which is what a 1 and 2 (respectively) fall under are good

***EDIT***

As long as that is what you actually earned and deserve.