I am on Tier 2 ICT established staff visa in UK and recently got an offer from another employer to switch to tier 2 general. New employer sent COS but it has following issues They submitted COS without asking me to verify draft version

1. passport number is incorrectly mentioned (they put letter O instead of Zero)
2. COS start date is on 1st Apr. I got 1 month notice with current employer and told them that i cant start by 1st Apr but HR is saying you can continue working with old employer after 1st Apr and join new employer at any later stage. As far as i read in this form, I can't work with old employer beyond the COS start date of new employer. could you confirm please?
3. RLMT comment says the job is advertised from 6th Jan - 26th Jan which counts only 26 days. Is this valid or it should be exactly 28 days
4. they mentioned Tier and Category field as Tier 2 (General - Changes of Employment) - Is this the correct one to use when we switch from ICT to tier 2 general?
Need your advice on how to handle this. I heard some details in COS can be amended in SMS. if it is amended, will it have any impact on decision. I am worried that there are too many errors here

Please advice.
Thanks in advance..