Depends what you eat. Generally speaking, it is more difficult because you only chew at about 50% chewing efficiency with complete upper and lower dentures. The main reason being that the dentures move. As a consequence, it's more difficult to eat harder, crunchier foods. Biting into sandwiches can also be challenging for some. So, if you like to eat these types of foods, like most of us do, then you may have a problem.
Dentures - yes. False teeth, as in full dentures, definitly make it harder to eat. Because they are less stable they move around when you chew and may make it impossible to eat chewy and/or sticky foods. They may also interfere with taste making food less enjoyalbe to eat. They are a course of last resort.
Can be. Denture teeth are much less efficient as far as chewing than natural teeth. Hard and chewy foods are usually more difficult, so be patient.
Yes. All the chewing studies done on denture wearers compared to people with natural teeth show that denture wearers can't chew with as much force and have more difficulty with certain foods. Gum tissues, of course, were never intended to withstand chewing forces like teeth in bone.
Can be . False teeth i assume you mean dentures or a plate. It can be challenging sometimes. However, if you have full plates it is difficult to eat, chew, laugh and speak however you want. Consider dental implants which can provide a permanent solution. Removing false teeth 3 to 4 times a day to clean and to keep applying fixodent can be very inconvenient.
Commitment! It is more difficult to eat with them but i would be motivated to practice eating and talking right when i get them. Practice makes perfect as they say.