The edge marks look like the effect of bubbles at or near the surface of the developer. There are a bunch of factors that can contribute to these, including insufficient developer in the tank, not enough vigorous agitation at the very beginning, failure to give the tank an initial rap to dislodge bubbles, use of water that tends more toward foaming than some other water - if you search the fora you will see that some have more problems with this than others.
The other, much fainter marks look mostly like the result of uneven agitation - particularly at the beginning of development.
Some will recommend a water pre-soak. Others will decry pre-soaks as the work of the devil! I am in the first camp (I use a three minute pre-soak with continuous agitation for all my films) but many don't and get good results. The manufacturers are either silent on the subject of pre-soaks, or say one is "not recommended", which depending where you live, may either mean don't do it, or it is not necessary to do it.
The initial agitation - first 30 seconds or so - is very important. Don't be afraid to approach it with vigour!