No they are different. Merchant is based on profession. It is for business/commercial purpose, not individual use.
Current account is based on liquidity requirement. It can be for personal or business use. Savings account has limit depending on variant cash withdrawal limit, Debit/pos limit. In Current you choose instant access to your monet in return you let go of interest.
How are you planning to pay ? You do have to pay mdr and other network charges. Pos has low charges. Charges on Upi through rupay cc is very high. Both would be generally higher than reward you would get from cc. Not to mention bank blocking your cc, chances of reporting to credit bureau. Also Technically it is fraud, even though bank don't pursue it. With more than 10L annual cc payment, it will show up in ais and might warrant a itd notice.
With transactions more than 20L in current account, if you don't have gst registration there is one more stress. Is it really worth it?