However, my pink lines are more than a little 'off' the roads. Two questions...1) did I reduce the trackpoints down too much in bike hike (from 1700 to 250) or should I get it to tie in to the nearest road?
Well I'm tempted to say - does it matter? - but that aside -
All the online planners tend to generate more trackpoints than are really necessary, so the option to downsample is very useful. However all Garmins can handle 500 points in a Track so it's never necessary to go below that. I don't have an E30 but I'm fairly sure that model will handle a Track of 1700 points (or even considerably more) without problems. The 500 limit is gradually becoming a thing of the past, that most new adopters don't need to worry about.
The other thing is, you planned your track using Google Maps, and now you're following it on an OSM map. By definition, these are not the same (because OSM's mappers are prohibited from copying other maps such as Gmaps). So two different data sets, and several different surveys. So in any given spot on the planet, one will be more right than the other. Which is the more right, could be either, will vary from place to place. So if you look very closely, a Track planned using Gmaps is unlikely to follow exactly, an OSM map. Though at most practical zoom levels it's probably not noticeable.
To get a line that follows exactly, you have to go back to using a Route file (as opposed to Track) which must have 50 points or fewer, and set the GPS to route 'on road for distance'. (Actually I suggest setting the GPS routing to 'prompted' - and then you get offered that choice when you load the route.) Assuming the map has embedded routing information, the pink line will now follow the roads. However there is a near-certain chance that sooner or later it won't follow the 'right' roads. That is partly down to the same problem as above - planning on one map but using another. It may also be partly fixable in the GPS routing settings. The routing information in an OSM map is certainly not as reliable as that embedded in a Gmap or in Garmin's own maps. Some people get on with it OK, but it's just the luck of the draw really, whether or not your favourite areas have been well mapped.
There is an option to 'lock on road' in the menus, but I think that refers to the way the Garmin displays its own position on the map. It won't affect any GPX you are displaying. It just takes your actual found location (which might seem to be in a nearby field) and snaps it to the nearest road. It's not a setting I've ever used so I don't know if it also modifies the recorded tracklog to follow the roads, but I suspect it may do. Unless you're trying to do a survey (for example, adding a missing road to OSM) then there's no real harm in it either way.
