I don't think this has a lot to do with being a new reviewer. My experience has in fact been that due to time pressure, senior researchers make decisions on pap

I don't think this has a lot to do with being a new reviewer. My experience has in fact been that due to time pressure, senior researchers make decisions on papers for completely the wrong reasons. They pervert the cause of science because of the rat race. The one that really sticks out in the list, that I'm a stickler for, is "details". The devil IS in the details. If a paper can't communicate the important details, then how can you ever claim that your work is reproducible? If your work is not reproducible, then it has no place in a scientific journal. In my field, a lot of senior researchers haven't executed a line of code in years, so the natural feeling is that the "detail" isn't important. If your code is not open-source and can't be audited, you better have the details in place. Another thing that I think deserves A LOT more attention is the co-author list. There should be more in place to stop what's all too common: people forcing themselves, especially senior researchers, on to papers that they have no business being on. The setup in a lot of academic environments is such that this can't be tackled from the inside. I think this should be a fundamental part of a "reviewer manifesto": figure out who wrote the paper and if you can't, ask to find out.