QGIS » QGIS Application

I notice I get over 6000 lines of Python errors in the log on every startup. That can't be normal??? I've also seen several sudden crashes, where QGIS just instantly disappears for no apparent reason, with no crash dialog or stack trace, and no logging I can find. (Is there some place I haven't looked for logs?)

I'm new to 3.0.3, so I'm not sure what is normal, but it seems very slow to start up, and operation seems to have "interesting quirks". Maybe all these errors are the cause?

Like suddenly today I can't create shapefiles...
#19158

And I get the following 17 lines of "Processing" warnings, and they repeat occasionally at times I haven't linked to any actions yet:

 
2018-06-13T12:19:19 WARNING Duplicate algorithm name clusteranalysis for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name confusionmatrixpolygonsgrid for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name gwrformultiplepredictors for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name gwrforsinglepredictorgriddedmodeloutput for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name gwrforsinglepredictorlayer for provider saga
2018-06-13T12:19:19 WARNING Duplicate parameter SEARCH_POINTS_ALL registered for alg inversedistanceweightedinterpolation
2018-06-13T12:19:19 WARNING Duplicate parameter SEARCH_POINTS_MAX registered for alg inversedistanceweightedinterpolation
2018-06-13T12:19:19 WARNING Duplicate algorithm name clusteranalysis for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name difference for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name polygonidentity for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name intersect for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name polygonselfintersection for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name symmetricaldifference for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name polygonuunion for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name regressionkriging for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name simplekriging for provider saga
2018-06-13T12:19:19 WARNING Duplicate algorithm name polygonupdate for provider saga

I'm on Windows 10 64-bit:

QGIS version 3.0.3-Girona
QGIS code revision 8a899c8758
Compiled against Qt 5.9.2
Running against Qt 5.9.2
Compiled against GDAL/OGR 2.2.4
Running against GDAL/OGR 2.2.4
Compiled against GEOS 3.5.0-CAPI-1.9.0
Running against GEOS 3.5.0-CAPI-1.9.0 r4084
PostgreSQL Client Version 9.2.4
SpatiaLite Version 4.3.0
QWT Version 6.1.3
QScintilla2 Version 2.10.1
PROJ.4 Version 493

Any clues how to explore this further?