Monitoring the amount of connections for each node

Yes, you can...

In SNMP it's in the LtmPoolMemberStatEntry structure. You have the right file, it's in the F5-BIGIP-LOCAL MIB file. Line 2710 on the file I just grabbed from v12.1

LtmPoolMemberStatEntry ::=
        SEQUENCE {
                ltmPoolMemberStatPoolName                              LongDisplayString,
                ltmPoolMemberStatAddrType                              InetAddressType,
                ltmPoolMemberStatAddr                                  InetAddress,
                ltmPoolMemberStatPort                                  InetPortNumber,
                ltmPoolMemberStatServerPktsIn                          Counter64,
                ltmPoolMemberStatServerBytesIn                         Counter64,
                ltmPoolMemberStatServerPktsOut                         Counter64,
                ltmPoolMemberStatServerBytesOut                        Counter64,
                ltmPoolMemberStatServerMaxConns                        Counter64,
                ltmPoolMemberStatServerTotConns                        Counter64,
                ltmPoolMemberStatServerCurConns                        CounterBasedGauge64,
                ltmPoolMemberStatPvaPktsIn                             Counter64,
                ltmPoolMemberStatPvaBytesIn                            Counter64,
                ltmPoolMemberStatPvaPktsOut                            Counter64,
                ltmPoolMemberStatPvaBytesOut                           Counter64,
                ltmPoolMemberStatPvaMaxConns                           Counter64,
                ltmPoolMemberStatPvaTotConns                           Counter64,
                ltmPoolMemberStatPvaCurConns                           CounterBasedGauge64,
                ltmPoolMemberStatTotRequests                           Counter64,
                ltmPoolMemberStatTotPvaAssistConn                      Counter64,
                ltmPoolMemberStatCurrPvaAssistConn                     CounterBasedGauge64,
                ltmPoolMemberStatConnqDepth                            Integer32,
                ltmPoolMemberStatConnqAgeHead                          Integer32,
                ltmPoolMemberStatConnqAgeMax                           Integer32,
                ltmPoolMemberStatConnqAgeEma                           Integer32,
                ltmPoolMemberStatConnqAgeEdm                           Integer32,
                ltmPoolMemberStatConnqServiced                         Counter64,
                ltmPoolMemberStatNodeName                              LongDisplayString,
                ltmPoolMemberStatCurSessions                           CounterBasedGauge64,
                ltmPoolMemberStatCurrentConnsPerSec                    CounterBasedGauge64,
                ltmPoolMemberStatDurationRateExceeded                  CounterBasedGauge64
        }