I think it's time for experienced players to start writing "strategy and tips" articles. Not just per faction, but overall because the principles apply regardless of clan. I had mucked around with Hojo but never seriously. My main H and VH campaigns were with Uesigi, Oda and Date. Once I got the hang of it I managed to win on Legendary with Uesigi (and I'll never play Legendary again!)
Two days ago I decided to give the Hojo a serious play.
In my experience Hojo is THE easiest faction I've played on VH. Now before you flame me, it is the reason I've written the first sentence. Once you get used to how the game works, and how that should affect your first few years, you can get away to a decent start. With Hojo already starting with two provinces - both "specials" - this is even easier.
One trick with the diplomacy is to NOT go for every trade agreement possible. Look at who is allied to who, who is trading with whom. If you don't want to upset a clan, don't make agreements with their enemies. Another when it comes to choosing allies - pick the dependable ones. And again, don't make an alliance if it'll upset the clan you're most threatened by (at that stage in your game). If you're going to hit someone, don't make agreements with them. But if you have one, break it at least a turn before you DOW on them.
At start build maximum troops for a minimum of 4 turns. Then keep building up troop numbers after the initial surge. This means at best one building upgrade per turn early (sometimes none). But troop numbers are critical, and more critical than your economy early. The Ai tends to respect military power more than anything else. Focus your few building upgrades on what is MOST important to you - be it a samurai dojo or a special building and usually a port. All else should wait until you get to around 4 or so provinces. The Ai also seems to respect money in the bank account. Don't try turtle until about 5 or 6 provinces. Then actually try to turtle - this is when you can really build up everything. You don't need peace to turtle, just "controllable" war (ie not an all in gang bang on you).
The above, irrespective of clan, will get you off to a good start.