Your question about the right to live in a property when you own 25% is more a legal than a tax question but is probably best solved by agreement with your daughter. However, you need to be aware that making a gift with ties could be treated as a gift with reservation of benefit and be ineffective for IHT purposes in that the seven year clock for the value of the gift to leave your UK estate won't start until the reservation comes to an end.
If you give your daughter 50% of your 50% (assumed) interest of the property no later than 5 April 2015, it will be a disposal for Capital Gains Tax purposes as well as a gift for Inheritance Tax purposes. As you are non-resident, the paper gain will be exempt from CGT. The gift will fall out of your UK estate for IHT purposes so long as you live for seven years after making the gift. Taper relief which you can read about here
can reduce exposure to IHT. Decreasing term assurance can also cover a potential liability to IHT.
As far as the rental income is concerned, as the property is not owned by a married couple or a couple in a civil partnership, you and your daughter can split the rental income in whatever proportions you like for tax purposes regardless of the ownership shares.
The UK government plan is for CGT to be applied to gains by non-UK residents on the disposal after 5 April 2015 of UK residential property but only on the difference between the disposal proceeds and the value of the property on 5 April 2015. In effect, the value on 5 April 2015 will become the cost for CGT purposes of any share of a property owned by a non-UK resident.
I'm not sure what you mean by "which solution for the rental property?". If you wish to benefit personally from the potential future growth in the value of the property, you have to accept that you are likely to have to pay CGT as many UK resident owners of let property do every year. Your son's share of any gain would be taxable as the property is clearly not his main home.
I hope this helps but let me know if you have any further questions.