Thanks for your interest in helping us in improving our map :)
First about your issues:
Splitting can be easily done in JOSM using "p" key when you select the node at which you want to split. If a separated cycleway merges again to the road, just connect them and (maybe) mark the waysegment beyond with a cyclelane tag.
You can use a highway=path
way and set the access=*
tag as needed. Also JOSM offers you for the most cases appropriate tag templates.
http://wiki.openstreetmap.org/wiki/Bicycle_route
See MTB
So in short, there is no guide on tagging for that dedicated scenario.
But there are several maps that render OSM data for the perspective of cyclists:
So we need to be a bit more accurate on who is the person who likes to benefit from your contribution:
MTB:
Usually uses off-road tracks in the wild and mountains or dedicated parks
http://wiki.openstreetmap.org/wiki/Mtb
BMX:
Similar to MTB but usually more city parks and not long routes
http://wiki.openstreetmap.org/wiki/Tag:leisure=track
Racing cycles:
Usually on dedicated tracks (see BMX) or on the road network. There they care about a very smooth surface and need good paving
http://wiki.openstreetmap.org/wiki/Key:smoothness
http://wiki.openstreetmap.org/wiki/Surface
Trekking:
Riding very long routes (maybe multiple days) and use cycling networks
http://wiki.openstreetmap.org/wiki/Bicycle_route
General:
The most of the types above share the same additional requirements because of the nature of bicycling.
The bike can break:
http://wiki.openstreetmap.org/wiki/Tag:shop=bicycle
http://wiki.openstreetmap.org/wiki/Tag:vending=bicycle_tube
Emergency:
http://wiki.openstreetmap.org/wiki/Tag:amenity=hospital
http://wiki.openstreetmap.org/wiki/Tag:amenity=doctors
http://wiki.openstreetmap.org/wiki/Key:emergency
Weather:
http://wiki.openstreetmap.org/wiki/Tag:amenity=shelter
The driver needs a pause/supply:
http://wiki.openstreetmap.org/wiki/Tag:amenity=bench
http://wiki.openstreetmap.org/wiki/Tag:amenity=shelter
http://wiki.openstreetmap.org/wiki/Tag:tourism=picnic_site
http://wiki.openstreetmap.org/wiki/Tag:amenity=bicycle_parking
everything else in tourism from fast_food to hotel http://wiki.openstreetmap.org/wiki/Key:tourism
-parken
As OSM data schema is always work in progress, this list is far from beeing complete, but IMHO it covers the most important aspects.