It should be stated first of all that getting approval or a promise from a girl’s parents to marry her as well as formal engagement are nothing more than a promise to marry at a future date. It is not at all a license for the parties to be together, to hold hands, or isolate with one another. None of these things are considered permissible; for such a promise or engagement does not make what is otherwise unlawful as lawful; therefore, for all practical purposes they are still considered as strangers.
The eminent Muslim scholar Sheikh Muhammad Al-Hanooti, member of the North American Fiqh Council, states: Any communication between a male and female before marriage should be for a certain pure and healthy cause. If they speak to each other, they should speak what they can say to each other in public. If their communication is romantic, seductive and desirous, that is not allowed in Islam because it leads into unlawful drastic actions.

You cannot touch a girl. Of course, you cannot kiss or do anything of what you ask about in the question. I do not know if you will allow somebody to do that to your sister for the same purpose. You remind me of many people who tried to find a justification and an excuse for what they do of haram, even though they feel that there is something wrong with what they do.
Anything before the marriage contract should be handled exactly for the interest for the boy and the girl. Therefore, communication between the two parties should be under the supervision of their parents. Anything secret here is wrong and haram.

Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, adds: You are not allowed to kiss this girl before marriage; such an act is considered absolutely sinful in Islam before marriage.

One is not allowed to touch or have intimate conversations or contacts with someone he or she is not married to. The fact you intend to marry someone or is engaged to someone does not make what is otherwise unlawful as lawful. So fear Allah and safeguard against temptations. May Allah help you to safeguard your honor and religion.