Hi Mead Mangler - I tend to agree with you. If you can get answers to specific questions here, that is good but often best answers are actually tied to whole philosophies and approaches and getting answers out of that context will suggest answers that can be decontextualized when they perhaps cannot be. Podcasts can be good but IMO they often contain chit chat that in all honesty I don't have time for (it's like listening to folk tell you about a dream they had. They are not always professional storytellers or good broadcasters. Their knowledge of the craft of broadcasting (or narrowcasting) is not always wonderful) Youtube videos tend to be as reliable self published books - no fact checking, no peer review, no editorial assistance and no sense of cinematography.. Trade books may be 20th Century but at least they are likely to have fact checkers, peer reviewers, editors and the like. Check out Ken Schramm and/or Steve Piatz. (amazon or your local library or brick and mortar bookstore... OK
1. Best yeast? Depends on what flavors you prefer in your meads, what flavors you really dis-prefer and what kinds of character you want to highlight in your mead. There is no wrong choice and my assumption is that most people select a yeast or two and stick with those (D47 , 71B for example) . That is certainly my approach BUT I also check out different yeasts that will highlight mouthfeel (DV10 D254) and /or highlight certain spiciness (saison yeast). Others (loveofrose, for example, tends to use Belgium ale yeast).
2. How much yeast? I would use 1 pack per gallon. Yes, a pack generally says that it is good for up to 5 gallons but wines are generally made from fruit and wines (and beers ) tend to have smaller gravities than what 3 lbs of honey will create. Home wine/mead-makers cannot really over pitch (too much yeast) but they can and do frequently underpitch and underpitching causes problems (including a taste and smell of yeast. Ironic, I know. And because the amount of CO2 being produced with small colonies of yeast is at any moment quite small there insufficient pressure produced to blow off chemicals that are the result of stress so hydrogen sulfide smells linger.
3. How much honey? That's like asking how long should a length of string be. It should be as long as you need /want. How much honey you use will depend on what kind of mead you are making. Do you want to sip this like a dessert wine? Then you want more honey. Is this to be quaffed like a beer or a cider? Then you want to use far less honey. Is this to accompany a meal like a table wine - then you want to use a quantity of honey that will give you an ABV of about 10-12%. Horses for courses. Also what other flavor components are you using? Do they add more fermentables? are they to be in balance with the yeast? are they to take center stage? Are they spear carriers?
4. How much nutrient to add? Different strokes for different folks. The package will have one set of instructions. Different protocols suggest other quantities. I am not convinced that SNA or TOSNA is worth the effort - and I generally aim for session meads (about 5% ABV) so I add my nutrients up front and I am very free with the amount I provide. Often a teaspoon per gallon. I am not concerned that the nutrients will leave tastes that I don't want. Yeast will gorge on the nutrient until the must is at 9% ABV and if my mead won't go above 5% then I will let others worry about my feeding protocol.
5. Degassing? Yes. CO2 adds stress to yeast (pressure) and while I generally make micro batches (often 1 gallon, sometimes 1 quart, occasionally 3 or 5 gallons) if, as I do, I ferment in a bucket then first thing in the morning and when I get home in the evening it is not any trouble to sanitize a spoon and whip the CO2 out of the bucket for a minute or two.. Once the gravity drops to about 1.005 I will rack the mead into a carboy sealed with a bung and airlock and then I don't touch it until either it is ready to bottle or I need to rack it again (because of the height of the lees (sediment)).
Hope all this helps. But the secret is to make mead AND read AND ask questions.