Do you wear gloves when handling raw meat- ground beef,chicken,fish, pork, etc?
for the tripping side of things i would try gettting you farrier to put road studs in your horses shoes as shoes are slippy compaired to bare feet. or perhaps try your horse unshod if he has strong enough feet. thought the tripping could also have underlying meanings perhaps he might have a stifle injury or a tendon as these can often make a horse trip/slip did you do anything that triggered the tripping e.g lunging or cantering on hard ground as these can trigger an old injury. are they older as it could be artheritis? for the spooking side of things doesd he just shy at every thing or is it bolting? i would suggest walking him calmly from the ground past these things let him sniff it so he gets used to it. good luck
If you have to ask, turn your power off.
For the spooky thing, it's just going to take time and patience to get him over that. Take things slow. If he's scared of something, make him look at it, approach it even, let him know it's not going to kill him. If you are riding when it happens, there's nothing wrong with dismounting - it doesn't teach them bad habits, Tripping? Sounds like your horses need to learn how to pick up their feet. Try and get hold of some trotting poles. Don't only get them to walk over the poles but create a maze out of the poles that you lead your horses through, make their aware of where their feet are. For the last thing, it's where you need to take your horses out. If they don't like others it possibly means that they haven't been socialized properly and just don't understand how to act. Ask around and see if you can just take your horses to some local shows so they can get a feel of the scene and the number of horses that will be there.
1) do ground work to build the horses trust with you then do basic work with a lounge whip drape it over their back and work on it until you can rub him all over even around the hooves and neck with it. then use a plastic bag on the end and do the same. you can also walk them over tarps and anything really. just try to do ground work and get them used to scary things. and rember if you look at the scary thing then it makes ur horse worry theres something to worry about so dont look at it. we have horses at my barn that spooked at nothing at all just spooked to spook and now they stand quiet as can be while we bounce a ribber ball off of their stomach or barrel 2) call a farrier out usually horses trip when their hooves are sore or overgrown. if they need to be trimmed or they may need shoes or something else i would call your farrier out to take a look.
I can only answer the first part, sorry. Horses need time to become used to new sounds. They may not know what it is, and that is what spooks them. How long have you had these horses? They may need just a little bit of time to adjust. I may be a horse fanatic, but I'm only twelve. Hope my answer helps, xoxox Shawty.