To the best of my knowledge, you don't need to notify the freeholder that you're planning to sell the lease.
Try to find a licensed conveyancer, rather than a solicitor, to sell the property. (My own experience is that they're cheaper and more efficient).
You're free to give your money to whomever you like, for them to do whatever they want with. (There's no such thing as 'gift tax'). However if you needed to go into a home in the future, it's possible that the local authority might take the view that you'd deliberately sought to avoid contributing to care home fees. (There's no time limit but the likelihood of that happening would probably diminish over time):
http://webarchive.nat...CareHomes/DG_10031523
Also, if you were to die within 7 years of the transfer of funds, all or part of the amount you've given away could still be counted as part of your estate when assessing whether that estate was liable for inheritance tax:
http://www.hmrc.gov.u...ey-property/index.htm
Chris