RockEngineer... I think I've spoken to you before re. log construction. Anyhow, two issues here:
1) Not clear how/why you justify dowel bearing strength vs. tab values for bolts in wood. Would still seem that the failure mode is the wood giving out.
2) With the thru rod...
CONCENTRATED LOADS ON LOG WALLS: Obviously this depends on the variables: log size & species, length of wall section, the corner construction (or lack thereof, e.g., if there are doorways, or window openings, or occasionally interior walls with no corner(s)), and the actual wall construction...
LOG STRUCTURES: Log Wall design for concentrated and lateral Loads: While these are typically issues we deal with in just about any log structure, I've never seen any "textbook" examples of how this is done.
For concentrated loads on walls, we typically resort to wood or steel...