Is it possible to pass parameters to pt-table-checksum using an options file?
Yes, you can do this.

pt-table-checksum --config FILENAME


Where FILENAME looks like

tables                  = table1,table2,table3
ignore-tables-regex     = ^tmp
chunk-time              = .2
max-load                = Threads_running=10
chunk-size              = 100000
user                    = myuser
pass                    = mypass


If --config is not specified, pt-table-checksum will read from /etc/percona-toolkit/pt-table-checksum.conf by default.  Nearly all Percona Toolkit tools have this ability.

Details on how the config files work is available here