Hello Grayland!
The reason that Mass times have eluded you: except on Sundays, morning masses are not as common in Spain as they are in other countries. During the week, Masses here tend to be in the evening almost everywhere. Also, in larger towns and villages along the Camino there may be parishes that have daily Mass, but in many of the smaller villages along the Camino, there is often only a Sunday Mass and one or two sometime during the week. The clergy in rural areas along the Camino (the meseta for example, or the Bierzo region) are stretched pretty thin and often have responsibility for as many as four or five villages spread out over a rather large area, so this means that they tend to do a circuit, offering Mass in one village one evening, another the next and so forth.
The following link will help you with finding Masses along the Camino:
http://www.misas.org This webpage lists Mass times in churches throughout Spain. It won't help with every village or town along the way because not every parish is listed, but it's a start.
At the top of the page, you have to enter the name of the village or city (
localidad), the day of week (
cualquiera=any day of the week,
festivo is a Sunday or Holy Day of Obligation,
vispera is vespers, the evening before a Sunday or Holy Day feast, and
laborable is a weekday) and the time that you are interested in finding a Mass. I experimented with it a bit, entering Navarrete (in La Rioja), Castrojeriz (in Burgos) Hornillos del Camino (Burgos), Cacabelos (in the Bierzo) and Portomarín (Galicia). I got info for Castrojeriz, Cacabelos and Portomarín, but nothing for Navarrete other than the name, address and telephone number of the parish, and nothing at all for Hornillos del Camino. Not really a surprise with the last one.
As for the churches being open along the way, they generally are not. The main reason is for security. Many of them, even in quite rural and out-of-the-way places, still contain valuable works of art in their Baroque tryptichs, and are kept locked to prevent theft or vandalism. It's an ongoing problem in Spain where art thieves have cleaned out rural churches of some very valuable images to such an extent that the Guardia Civil even has a unit specializing in the investigation of such crimes! That, plus the danger of the profanation of the Blessed Sacrament, which does not happen often, but has on occasion when churches have been left unlocked and unattended.
If the parish priest is not resident in the village, the key is often left with a parishioner who looks after the church, but this person obviously also has their daily tasks to attend to and cannot always be around to open the church and keep an eye on things, so the church stays locked for security.
Hope this info is helpful! God bless!