If for instance one was flying the above approach and the flap clean speed was 210kts, would you insert 210kts in the FMC at the FAF, which in this case is 10.6DME.
Would you then fly a decelerated approach in VNAV with speed intervention or would one create a WPT before 10.6 DME to be at 210 kts and then be totally configured at 10.6DME with Vapp+5.thereby flying the entire approach totally configured and stabilised.
I suppose you COULD fly it that way, but why bother? Boeing states: "Adding speed constraints to the final approach waypoints is not recommended because of the extra workload, no safety benefit and reduced ability to make last minute approach changes". Boeing also recommends using VNAV with speed intervention on the final approach.
It's far better to keep the process as simple as possible, rather than complicating things by adding extra speed constraints, waypoints, etc. I would fly the approach as follows:
1. Leave all speed constraints at their default values.
2. Fly the descent to the initial approach altitude in whatever mode you like - VNAV PTH, VNAV SPD, FLCH or VS. As you said, if you are being vectored off track, it might be preferable to use VS or FLCH rather than VNAV to maintain a reasonable descent profile.
3. Reduce speed as required, using speed intervention.
4. At some stage before the approach commences, select VNAV if not already selected.
5. When the FMC transitions to "on approach", the speed window will close, and the speed bug will move to the FMC speed. Be prepared, and open the speed window again and set the speed YOU want to fly. As Old Smokey said, the FMC makes no allowance for flap settings and will select a speed lower than the flaps up manoeuvring speed even if the flaps are up, so you must anticipate the speed window closing.
6. From then on, you will be in VNAV PTH with speed intervention. Make sure you have a lower altitude set in the MCP window, configure the aircraft and reduce speed on schedule using the MCP selected speed. Simple!