Tuoe doesn't always apply to every transaction so make sure it does - if your current company have told you it does, then it does.

It basically means all your current terms and conditions are protected for ever - there is no time limit for Tupe so the new owners technically can never change them. However if there is a genuine change of job role ie a promotion say, which you are offered and accept, then obviously the employer will offer you new terms which may be different to your old terms.
It will be up to you to accept but if you don't you won't get the promotion

Employers try to do mass changes agreed with trades unions - and many succeed if the terms are better. But this is technical agreement and the enforceable law would be your original contract. New employers quite often offer a sweeter to get people to drop their old terms and accept new one ie a pay increase, additional bonus, better benefits - but you don't have to accept them. Pensions remember are treated differently - changes can be allowed.

Redundancy terms from your current employer should transfer and if you are made redundant then the original terms will apply (unless you have accepted a new contract as above). Redundancy post a transfer can be tricky - you can't be made redundant because of the transfer itself but if there is a genuine need to reduce work or types of work you can be made redundant. Also you cannot be made redundant by your current employer before you are transferred - that would be illegal.

If a further business transfer happens, Tupe applies again; you will transfer with theorems and conditions in force at that time, which may still be your original terms.

Hope this helps - good luck! If your personal circumstances are difficult then best to get individual advice from an employment lawyer.