Japan is great when it comes to hit and run tactics. Like the soviets, they are very zerg-like in nature and have an interesting balance system to show this. Like the soviets, their tanks are cheaper than average, but the difference being that they are significantly cheaper and trade almost everything a tank can bring to the field in favor of a bigger gun.
Japan infantry may not be the cheapest, but they are most relient on indirect firepower and outside support, making them the only actual infantry that is not quite fit for fair combat.
Although they have the cheapest armor in the game, it's also the weakest. Most of the tanks a Japan player can field don't qualify for medium class.
Japan infantry are also the least useful in direct combat, as they heavily rely on knee mortars and other possible support weapons.
When it comes to the basic units of Japan, be prepared to work with certain gimmicks, as your infantry is pretty weak for the price you pay, but you get better support weapons. Commonly used in mixes between rifle squads and assult squads, the Japan knee mortar is a cheap, short ranged mortar that is easy to deploy in the front lines. It is free with every rifle squad and is usually used for creating large smoke fields for rapid infantry pushes that are nearly unstoppable when executed correctly.
One will rarely use Japan vehicles, as the tankettes are avilable extremly early. The use of transports is usually redundent for a Japan player, as even the mortars are mobile enough to get around on their own.
Japaniese tanks are made from the finest quality paper, providing almost no protection for the men inside. No self-respecting player will make high-level [Tank Destroyers] against even the best of Japaniese tanks. They do have some of the best weapons, being both long(ish) ranged and powerful. The armor on your tanks will range from 8mm to 40mm with rare exceptions, meaning you will be the only one having fun with light tanks.
The tankettes come in pairs and are the cheapest and most annoying little things to deal with, as makng a large number of those (or any JAP tank, for that matter ) is not something you will consider difficult. Supplying them is another story.
Japanise have slightly cheaper aircraft with their performance being proportionally less colorful. They still feel quite responcive and are just as potent when used against enemy units. To answer your question: no, there are no suicide bombers (unless spring decides there are, but all factions are equal here).
The Japaniese field gun makes the most noise out of them all and rightfully so: it doubles as one of the best short-ranged AT guns as well when comparing to other field guns. The AT weapons are similar in function to soviet guns, but are slightly slower to fire. Howitzers and similar fancy toys are available from the get-go and are not outstanding, despite the average Japaniese caliber for tanks being much higher than their equivelents.