Hi,
About the first problem (x_line_item) I think it is come from your currency configuration.
The plugin round the value using the currency configuration (number of decimal digits).
About the second problem (x_relay_response) I am sorry but the plugin has been made for Authorize.net and "First Data e4" seems to be compatible with their API.
But if you look at the authorize.net documentation about the x_relay_response
www.authorize.net/support/AIM_guide.pdf
x_relay_response Value: FALSE
Format: FALSE, F, NO, N
Notes: SIM applications use relay response. Set this field to false if you
are using AIM.
In other modes (SIM/DPM) the value "TRUE" is sent.
Regards,