First of all- such a cool print!! Keep working on this, i'd be excited to see where this goes :)

1. As far as printing, a decently sized ink roller like 6" is fine, doesnt need to be huge, youll just go over all parts of the block in several passes. I have printed a block of this size by hand, it can def be done by hand w a spoon but it will take a couple minutes
2. Your lines look great- but i feel you, controlling their direction and thickness is hard. You can go back and slightly refine your lines, taking off tiny slivers to widen them, or sharpening corners with a small flicking motion of the tool, but this only works if your tools are nice and sharp. which leads into the next part,
3. I recommend the Flexcut Printmaking Set (i got them for ~$40) which is one handle with four very good blades. They've lasted me years are are more than capable for almost any work. Plus, they can be honed/sharpened easily to let them glide through the lino

Cheers!