It may not appear polite, but the result is that Israeli's very rarely make violent contact with one another. As they come from a young and traumatic society where war has been the norm - trying to get the most out of today is the expected rule. If you are talking in terms of months and years - you may lose your Israeli partner's interest. In this circumstance he may very well perceive you as not being serious. Try to meet him or her half way - try to speak realistically in terms of days and weeks.
Meetings can be and are often spontaneous.
Again a reflection of the informal and family oriented culture. Punctuality is relaxed. Always allow up to 15-20 minutes before thinking that your party is late. Even here, things are rapidly changing, especially in the hi-tech environment where many Israelis pride themselves on being on time. After work hours, you may notice a more relaxed tone.