You asked

When can I take a bath or hot tub again after delivery?

If you think about it, water births are done in what amounts to a warm bath. A warm bath in a normal tub can help your body recover. Swollen labia, haemorrhoids and episiotomy injuries can all be soothed by warm water. Tension and fatigue can be relieved too. Having a bath gives you some private time to yourself, and allows you to give control of your child to someone you trust, so that your mind can be free for a little while.
If you have had a c-section, it is better to wait for at least a week, so that your incision and stitches do not become infected during the healing period. Bathing with mineral salts has a slight disinfecting action, and it can help you relax.
Using a hot tub is quite a bit riskier; the tub surface needs to be very clean and the water must be fresh – not weeks old. The chemicals used for sanitising, could affect your wounds, or swollen areas. It is best to wait at least six weeks before using a normal hot tub that hasn't been specially prepared for you. Infection is a big danger in the early days after delivery. While your body is recovering, you may still experience lochia flow, seeping from tears or cuts and maybe even incontinence. This can make the hot tub unpleasant and a health risk for others.

More questions

Yes, breastfeeding has a direct effect on the size of your uterus.
The general consensus among healthcare providers is that it is safe to have a nice warm bath straight after delivery.
Some doctors, and many women as well, have reported that applying raw, cooled, cabbaged leaves to the breasts helps to reduce milk production and the discomfort that comes with having engorged breasts as well.
It is not a good idea to use tampons until you are completely healed after giving birth. If you become infected because of a tampon, it only means more pain and a longer time to recover after giving birth.
What took your body nine months to develop, takes a matter of weeks to transform you back to the woman you were before your pregnancy. It is no wonder that most women feel totally exhausted after giving birth. Your brand new baby is of course, your amazing reward.
After a vaginal birth, it is considered normal to have swollen, tender labia.
If you’re planning a post pregnancy trip, make sure that you bear a few guidelines in mind.