Yodlee creates statement level transactions only for credit card accounts and not for checking or savings account and hence you are not getting statement for checking but you are getting that for credit card. Also you should not be using getItemSummaryForItem1 for getting transactions as this API creates a huge load on Yodlee's servers and hence there is another API called executeUserSearchRequest in transactionSearchService which should be used for retrieving transactions.
Below data extent level should be used to only get the account level details.
BankData
dex.startLevel: 0
dex.endLevel: 0
CardData:
dex.startLevel: 0
dex.endLevel: 0
For cards to get statement level data the dataextent should be
CardData:
dex.startLevel: 0
dex.endLevel: 2
and for data including statement bill level -
CardData:
dex.startLevel: 0
dex.endLevel: 4