It also depends on which chart you are taken into consideration to determine the trend, on a daily chart I still see a long term uptrend, on one hour or less a short term downtrend or consolidation from this uptrend.

Yes, on the daily chart it does look suspiciously like a consolidation pattern. A break of that top resistance line might yield some good long pips.

EUR/USD is at 1.455 now. Is it good to buy?

As a rule of thumb I trend with the 60M or 4-hour trend. It is much easier to go with the flow than to try and call a top/bottom. Right now the 60M trend is bearish so I would not be looking for long entries.

If the pair is close to the 14680 mark but is a few points short,and it starts the downward trend , is that a valid trade?

Smartchick, it depends on how big/small you want your stop-loss to be. Some traders are OK with a 50-80 pip stop loss so enter earlier. Others want to risk less and wait for better entries, but get in less trades. It depends on how good the setup is and what your money management is. Read the article on the left on money management.

Mark, which chart do you use to determine this failure signal?
Vice versa, on which chart do you determine a broken resistance?
Do you enter once r/s has been broken, on the the first rejection or on a consecutive rejection?

If I am looking for a failure signal I will usually look on 30m and 60M charts. For broken support/resistance I like a close on the 60M chart, generally at least 15 pips above/below support/resistance – but this is variable and depends on the setup. Once broken, and again this depends on the setup, but I like to enter 5-10 pips below the wick high/low or 10-15 points above resistance.