I'm by no means and expert, but I did some research on late medieval agriculture in Europe. Agriculture could be widely diverse, depending on the region. That being said, I'll try to share some things I remember, keep in mind that I'm not a native speaker so some of the terms used might be less common in English :

a. This depends on the kind of products. Generally they used to Three-field system combined with different products. When they should plant what was largely determined by experimental knowledge passed on through generations. It also differs from region to region. Keep in mind that potatoes weren't widely used untill around 1700, so there was much more incentive to diversify production based on region and climate. Generally, mild weather was desired. They realized that both draughts or intensive rain were equally bad for most crops. Especially too much stagnant water when the temperature was somewhat warm could yield bad results for a lot of crops.

b. All depends on the crop and the amount of land. Some crops had shorter cycles and needed to be harvested often, others required a lot less care and planning. What you would often see were bigger farmers recruiting the help of the local community when it came to harvesting. In exchange, they could for example use his horse to plow their fields - if already common practice in the region in question. Networking within local communities was often very important. People relied on eachother and helped eachother out.

c. In most medieval regions, hunting would be reserved for the local elite. Those popular stories about commoners getting caught punished for poaching, aren't too far fetched. That being said, most local communities had "common grounds" and "common forests". These common grounds were usually grassy fields were everyone who owned cattle (usually only the bigger farmers) could let them graze. The "common forests" were sometimes used for hunting small game, but mostly they were used for foraging.

d. Catastrophic field yields would often lead to hunger and sometimes even death. People would become malnourished and die to disease, cold or simply hunger. Especially towards the later middle-ages, you have to remember that many farmers weren't producing for themselves. Sure, they sometimes had their own little field where they would grow crops for personal use, but a lot of them were producing products for a market. Ranging from beer production to the production of clothes. This is especially true for the regions in Central Europe. For example the Low Countries were as early as 1400 dependant on grain importation from Baltic regions. Producing for a market occured much earlier though, check this out of you are interested. Some more remote regions were more self-sustainable, but they would still be in dire straits when disaster struck. In some more populated regions, local municipalities would store grain just in case, but this usually only made things slightly more bearable.

e. Again, depends on the product. Most grains could be stored fairly long and effectively and thus was often used as a "backup" for when crop yields were dissapointing.

f. Mostly seasonal food. There were some methods to keep products "fresh" longer, but this was all fairly limited. I'm not sure how widespread this was, but sometimes fruit which was starting to turn bad would be used or sold in order to make beverages.

g.Hard to gauge. Depends on the region. Obviously fishing was more important in some regions. When there were fishing grounds or grounds to forage upon present, they were often used as an important supplement to the local diet. Also keep in mind that in Central Europe at this time, most people were Catholic and a big portion of their diet and how they interpreted the yield of their crops was related to religion. Again, it differs from region to region.